WPI FL-MFCS Microfluidics Control System Instruction manual

INSTRUCTION MANUAL

Serial No._____________________

FL-MFCS

Microfluidics Control System

011211

World Precision Instruments

MicroFluidics Control System

ii

WORLD PRECiSiON iNSTRUMENTS


CONTENTS

ABOUT THIS MANUAL ............................................................................................................................... 1

INTRODUCTION ........................................................................................................................................... 2

Parts List ..................................................................................................................................................... 3

Unpacking ................................................................................................................................................. 4

INSTRUMENT DESCRIPTION .................................................................................................................... 5

Required Materials .................................................................................................................................. 5

Setup ............................................................................................................................................................ 6

Starting the MFCS .................................................................................................................................12

OPERATING INSTRUCTIONS ...................................................................................................................14

Purging .....................................................................................................................................................14

Controlling Pressure in the Channels .............................................................................................15

Tab Configurations ...............................................................................................................................16

Saving Curves .........................................................................................................................................16

Coupling ...................................................................................................................................................17

Manual/Auto Modes ............................................................................................................................18

Feedback Coefficient ............................................................................................................................18

MFCS Mat (Scripting Software) .........................................................................................................19

General Description ........................................................................................................................19

Description of the Table ................................................................................................................20

Descriptions of the Actions ..........................................................................................................20

Script Example ..................................................................................................................................20

Labview ....................................................................................................................................................21

Labivew VI .........................................................................................................................................21

Labview Examples ..........................................................................................................................24

Control 2 MFCS ................................................................................................................................24

Calibration .........................................................................................................................................25

Set Pressure and Alpha–Analog Display ................................................................................25

Set Pressure–Digital Readout ......................................................................................................25

C++ and VBA .........................................................................................................................................26

Function Description (preliminary) ...........................................................................................26

VBA Declarations Examples ........................................................................................................29

About Output Pressurization .............................................................................................................30

MAINTENANCE ............................................................................................................................................31

ACCESSORIES ...............................................................................................................................................32

SPECIFICATIONS ..........................................................................................................................................33

MFCS 25 mBar .......................................................................................................................................33

MFCS 70 mBar .......................................................................................................................................33

MFCS 350 mBar.....................................................................................................................................34

APPENDIX A .................................................................................................................................................35

Response and Stabilization Time ....................................................................................................35

Unit Conversion Table .........................................................................................................................35

Copyright © 2011 by World Precision Instruments, Inc. All rights reserved. No part of this publication may be reproduced or translated into any language, in any form, without prior written permission of World Precision

Instruments, Inc.

WORLD PRECiSiON iNSTRUMENTS iii


Hydrodynamic Resistance of Rectangular Channels and Networks ..................................36

Trace and Log Flle Formats ................................................................................................................38

WARRANTY ..................................................................................................................................................40

Claims and Returns ..............................................................................................................................40

iv



ABOUT THIS MANUAL

The following symbols are used in this guide:

This symbol indicates a CAUTION. Cautions warn against actions that can cause damage to equipment. Please read these carefully.

This symbol indicates a WARNING. Warnings alert you to actions that can cause personal injury or pose a physical threat. Please read these carefully.

NOTES and TIPS contain helpful information.

Fig. 1—Flowell microfluidics system


1


INTRODUCTION

MFCS

Fluiwell

To your application

Soft

Tubes

Reservoirs

Fig. 2—Connecting the MFCS system

The MicroFluidic Control System (MFCS) is a high-precision, pneumatic pressure controller designed to handle fluid in microfluidics systems (microchannels and nanochannels, capillaries, Lab-on-chips…).

It allows a stable and pulsation free flow with short response times (100ms) and a stabilization time as low as 1s. With the MFCS it is also possible to control several independent channels (up to 16 cf Labiview VI) simultaneously. The user friendly software allows you to create scripts for complex flow patterns or dynamic coupling for usercontrolled dependence between channels.

Channels

4 Channel

MFCS-4C-25 MFCS-4C-70 MFCS-

4C-345

8 Channel

Pressure type

0–25 0–69

Pressure Range (mBar)

0–345

MFCS-8C-25 MFCS-8C-70 MFCS-

P>0

8C-345

0–1000

MFCS-

4C-1000

MFCS-

8C-1000

-25–0

MFCS-NEG-

4C-25

MFCS-NEG-

8C-25

P<0

-69–0

MFCS-NEG-

4C-70

MFCS-NEG-

8C-70

2



Parts List

After unpacking, verify that there is no visible damage to the instrument. Verify that all items are included:

(1) MFCS unit

(1) power supply and a power line cable

(1) USB cable

(1) pneumatic connection kit (4 soft tube adapters, 4x50cm of soft tube (OD 3mm ID

1mm), a ¼" wrench) For a 8 channel MFCS, 8 adapters are included.

(1) Instruction Manual

Fig. 3—Parts of the MFCS system

FEP Caps

Fluiwell Reservoirs

Fig. 4—Optional accessories for the MFCS system include a Fluiwell and a set of spare parts.


3


Unpacking

Upon receipt of this instrument, make a thorough inspection of the contents and check for possible damage. Missing cartons or obvious damage to cartons should be noted on the delivery receipt before signing. Concealed damage should be reported at once to the carrier and an inspection requested. Please read the section entitled “Claims and Returns” on page 40 of this manual. Please contact WPI Customer Service if any parts are missing at

941.371.1003 or [email protected].

Returns: Do not return any goods to WPI without obtaining prior approval (RMA # required) and instructions from WPI’s Returns Department. Goods returned (unauthorized) by collect freight may be refused. If a return shipment is necessary, use the original container, if possible. If the original container is not available, use a suitable substitute that is rigid and of adequate size. Wrap the instrument in paper or plastic surrounded with at least 100mm (four inches) of shock absorbing material. For further details, please read the section entitled “Claims and Returns” on page 40 of this manual.

4



INSTRUMENT DESCRIPTION

Rear View

Pressure Inlet

USB

Power Supply

On / Off Switch

LCD Pannel

(Displays input pressure when grren button on)

Front View

Green Button

Red Button

Fig. 5—MFCS front and rear panels are labeled.

Pressure outlet

Required Materials

The MFCS requires the following materials:

• A computer:

• USB 1.1 port or faster

• Screen resolution of

1024x768

• Intel Pentium II 500 MHz or faster

• Windows 2000, Windows XP

• 5Mb of free disk space

Norgren

(F07-200-A3TG)

Pump of Local

Pressure Network

Air drier

• A pneumatic pressure source:

• Dry, non-corrosive (use an air drier)

• Dust and oil-free

• Pressure regulator to tune the input pressure value

• 0.01µm Filter

• Pressure range of the pump to suit your MFCS input pressure (Fig. 6)

Norgren

(F72C-2GD-QT0)

Particle filter 0.01µm

Gas Cylinder

Or

Pressure

Regulator

Watson Smith

(LS6 2RT)

Only for positive pressure

Fig. 6—Suggested pressure source scheme


5


Pressure Range mBar 0 to 25 0 to 69 0 to 345 0 to 1000 –25 to 0 –69 to 0

Input Pressure value

PSI

PSI

0.35

mBar 500

7.25

1.00

500

7.25

5.00

800

11.60

14.50

1300

18.86

–0.35

– 500

–7.25

–1.00

– 500

–7.25

Fig. 7—Input pressure value according to the MFCS pressure range

Connection to the MFCS requires either:

• The Fluiwell, a microfluidic interface between the MFCS and your Microdevice that uses 1/16’’ OD tube or smaller (see Fig. 8)

• Your own connection system

To microfluidic

application

Controlled pressurized gas from MFCS

Fig. 8—Fluiwell's working principle

Setup

WARNING: MFCS MUST BE USED IN A CLEAN AND DRY ENVIRONMENT.

WARNING: NO LIQUID SHOULD ENTER THE DEVICE. THIS VOIDS THE

WARRANTY.

WARNING: THE PRESSURE SOURCE MUST BE DRY, DUST AND OIL FREE.

USE A 0.01µm FILTER AND A PRESSURE REGULATOR TO INSURE PROPER

INPUT PRESSURE.

6



Fig. 9—Setting up the MFCS with Fluiwell

Please follow the next series of operation in order to set properly your MFCS.

1. Unpack the MFCS.

NOTE: If something is damaged, email [email protected].

Fig. 10—MFCS unit

2. Make the following connections on the rear panel:

• USB cable

• Power supply

• Pressure source

RUN CLEAN, DRY GAS THROUGH A PRESSURE REGULATOR BEFORE CONNECTING

THE PRESSURE SOURCE TO THE MFCS. (See "Required Materials" on page 5)

Fig. 11—Connections made to the back panel

3. Insert the MFCS software CD into the computer. Copy the folder corresponding to


7


your device (MFCS-4C for 4 channels and MFCS-8C for 8 channels) folder to desired location on your hard drive.

Fig. 12—Folder icons shown on the CD

4. Open the folder you just copied on your hard drive. Then double click on the software folder that has the same name.

5. Turn the MFCS ON using the switch on the rear panel. The red light illuminates to indicate that the power is on. If not, check the power supply and the USB cable.

Fig. 14—The red LED illuminates to indicate the power is on.

6. Double click on the MFCS control icon.

Fig. 15—The MFCS icon is highlighted in the image.

7. The software opens and is ready for use.

8



Fig. 16—MFCS software welcome screen

8. The pressure source must be CLEAN AND DRY and fixed to the input pressure value specified on the rear panel of your MFCS. It is located next to the input pressure valve of the MFCS.

Fig. 17—The label indicates the correct input pressure for your system.

Pressure Range (mBar) 25 69 345 1000 –25 –69

Input Pressure value (mBar) 500 500 800 1300 –500 –500

9. Press the green button and set the pressure source to the input pressure value of your MFCS. The preheating will start. A preheating procedure is necessary to warm up the MFCS (10 min.). Meanwhile, you can continue with the next step. Avoiding this step can decrease the pressure control stability and accuracy. Preheating is only necessary once a day.

Fig. 18— When the green button is pressed, the green LED illuminates (left) and the warning appears on the computer screen (right).

10. Unpack the Fluiwell (optional accessory, not included). Verify that the four toric seals


9


are in place, before mounting the reservoirs.

Fig. 19—A toric seal is marked by the arrow in the image.

11. Screw the 2mL reservoirs on the Fluiwell.

Fig. 20—The reservoirs are in position.

12. Prepare your experimental setup by gathering all the devices and elements you might need. The length of the tubing corresponds with the distance between the

Fluiwell and the MFCS.

Microfluidic Chip

Soft Tubing

Microscope

FEP Tubing

Fig. 21—Position the system components as shown in the image.

13. The connectors that are included with the system are 0.0625". If you prefer to use

10



different connectors, see Appendix A for a list of suppliers. You can also find suppliers for the tubing in the appendix. You will need four pieces of soft tubing and four pies of FEP tubing. (For the MFCS-8C, you will need eight pieces of each.)

Fig. 22—The included connectors are installed (left). The image (right) shows the soft tubing on the top and the FEP tubing on the bottom.

14. Connect the soft tubing to the Fluiwell.

Fig. 23—The soft tubing is connected.

15. Connect the FEP tubing to the top outlets. Screw the fitting down finger tight in order to avoid leaks. The FEP tubing should be visible inside the 2mL reservoirs.

Fig. 24—The FEP tubing extends into the 2mL reservoirs.

16. Your Fluiwell is ready to connect with your microfluidic chip and the MFCS. Before making the connections, fill the 2mL reservoirs with your sample.


11


Starting the MFCS

1. Remove the protection caps from the MFCS outlets. Use the provided wrench or any

¼" tool.

Protection Cap

Free Outlet

Fig. 25—Remove the caps from the outlets.

2. Tightly screw the soft tube adapters on the outlets

Fig. 26—Soft tube adapter are screwed into the outlets.

3. Connect the soft tubing to the MFCS outlets.

Fig. 27—The soft tubing from the Fluiwell is connected to the soft tube adapters on the

MFCS outlets.

12



4. Connect the Fluiwell to your microfluidic chip, using the FEP tubes. A list of adapters for smaller inner diameters tubes is available in the appendix.

Fig. 28—Connect the Fluiwell to the microfluidic chip.

5. Fill the 2mL reservoirs with the appropriate fluid corresponding to the inlets of your chip.

6. At the end of the preheating countdown:

• Push the red button

• On the computer interface, calibrate the MFCS by selecting Setup>Compensate offset. Click the Save to MFCS button to load your calibration parameters into the

MFCS and close the window.

In order to guarantee the accuracy of your measurements, we recommend calibrating the device every time you move it. Otherwise, once a month is sufficient.

The MFCS is ready to be used.

✔

✔

Fig. 29—MFCS Setup menu

Fig. 30—Offset Compensation Window

Fig. 31—Save to MFCS button


13


OPERATING INSTRUCTIONS

Here you will learn how to operate the MFCS using the MFCS control interface.

Preheating

Warning

Pressure

Handle

Pressure scroll

Coupling field

Direct

Button

MFCS

Status

Purge

Button

Requested

Pressure field

Config Tabs

Fig. 32—MFCS software control interface

Purging

1. Click on the Purge button. A warning appears asking for confirmation. Click Yes.

Fig. 33—Warning message

NOTE: A purge feature is available in channel 1. It applies maximum pressure on this channel. It suits any filling or emptying purpose.

2. To disable the purge, click the Purge button again. The Purge On (green) indicator appears until you stop the purge.

Fig. 34—SFCS Status window

14



Controlling Pressure in the Channels

There are two different way to modify the pressure in a channel:

1. Press the Direct Control button to activate the control of the MFCS. Otherwise, the orders will not be transmitted.

2. Then, choose one of the following options.

• Change the pressure in the channels, using the corresponding handle.

Fig. 35—Move the slider up to raise the pressure.

• Enter the numerical value of the pressure in the requested pressure field.

Fig. 36—Enter the desired pressure into the appropriate field to change pressure in the channels.

Keyboard Shortcuts:

• Up arrow: Moves the handle up one step

• Down arrow: Moves the handle down one step

• Page up: Moves the handle up 10 steps

• Page down: Moves the handle down 10 steps

• Home: Moves the handle to the top of the scale

• End: Moves the handle to the bottom of the scale


15


Tab Configurations

1. You can use the config tabs to set different handle patterns in order to easily switch between several pressure sets by clicking on the corresponding tab.

several pressure sets. An example is shown in the graph above.

2. The curves will follow the pressure pattern. (See "MFCS Mat (Scripting Software)" on page 19 or "Labview" on page 21 for automated pattern setting).

Fig. 38—This sample shows a pressure pattern with no curve.

Saving Curves

1. To save a set of curves, first choose the desired trace (sampling) rate.

Fig. 39—Choose File>Trace rate to select the desired sampling rate.

16



2. Choose File>Save Trace to start recording. Give a name to the curves file in Save

Trace dialog box of the file menu. (A check mark appears next to the Save trace menu item.)

Fig. 40—File menu with a check mark next to the Save Trace option indicates the system is recording, and the menu without a check mark shows the system is not recording.

3. To end the recording, choose File Save Trace again. (The check mark disappears.)

The trace file is saved as a text file that can be imported into any spreadsheet. The file looks similar to the example shown below.

03/09/2020 08 15:2

15:21:39

15:21:39

15:21:39

11463

11464

11465

1:39 MFCS Automat V:

174,942

175,258

174,942

140,017

140,017

140,017

1.05 MFCS S/N:0005 V:000B

0

0

0

0,105

0,105

0,105

03/09/2020 08 15:2 2:05 --EN D OF TRACE-

Fig. 41—The table shows the time of the experiment, the time step nº, pressure of channel

1, pressure of channel 2, pressure of channel 3 and pressure of channel 4. In addition it has a line to indicate the start and one for the finish.

For more information on curve file formats, see "Trace and Log Flle Formats" on page 38.

Coupling

Coupling is a feature that creates software driven dependence between channels. Thus, it is possible to increase pressure in one channel while the pressure in a second one is decreasing with the same variation. Both parallel and anti-parallel coupling are possible.

• To set a parallel coupling between channel 1 and channel 2, choose A + for both channels in the coupling field.

• To achieve an anti-parallel coupling, just choose A- for one of the two channels.

• To couple more than one channel, set the coupling field of each channel.


17


without changing the pressure sum. Parallel coupling keeps the pressure difference constant.

Keyboard Shortcut:

It is possible to temporally disable the coupling feature of a set of channels by pressing the shift key. Then, move the handles independently.

Manual/Auto Modes

The manual mode provides a proportional control on the valves. The handles directly control the valves opening, and no regulation occurs. This mode is only adapted for special use and it is subject to intrinsic nonlinear characteristics, hysteresis and limited reproducibility of the solenoid-valves.

The auto mode provides a direct control on the pressure inside the channels. The handles set the requested pressure and the embedded regulation program computes the command to give to the valves in order to have a stable, quick and reproducible response.

Feedback Coefficient

5

Fig. 43—In the first graph, the feedback coefficient is too high. In the second, it is optimized.

In the third, it is too low. These graphs show the effect of the feed back coefficient value on the pressure stability and response time.

The MFCS Control software provides optimal pressure and flow regulation for a wide range of microfluidic applications, in particular those involving extremely low pressures and or volume flow rates (µL to pL/min). However, when using large volumes, an

18



adjustment of the feed-back loop’s reactivity can be necessary to achieve optimal results. This can be achieved independently for each channel by adjusting the feed back coefficient.

The factory setting is 5, a smaller coefficient results in a slower reaction, a higher value gives a faster response.

If the feedback coefficient is too high, the regulation loop can become unstable and pressure control inside the channel is no longer possible. The optimal response is obtained just below the critical damping situation between a monotonous return to equilibrium and oscillatory overshooting (See Fig. 43).

NOTE: For high pressure versions of the MFCS, at the initial factory setting, operation is oscillation-free for small pressure changes but shows overshooting and transient oscillations for drastic pressure changes. If this overshooting is a nuisance to your application, it can be suppressed by decreasing the feedback coefficient. You will lose some of the regulation speed for small pressure changes. A working balance must be achieved. The optimal value depends on several features of the connected system, including: volume and elasticity of tubing, hydrodynamic resistance and geometry of the microfluidic channels and the time constant of the phenomena under investigation.

MFCS Mat (Scripting Software)

General Description

Chart

(here it is blank)

Table

MFCS Status

Fig. 44—MFCS Automat window

MFCS mat is a script software that allows you to create automated pattern of pressure.

In the main window (Fig. 44), you can find:

• A chart showing the pressure value of all the channels (here it is blank),

• Below the chart, the MFCS status is shown with the following buttons: Play,

Pause, Stop and Verify program.

• On the right hand side, you can add different actions in the table (script).


19


Description of the Table

In this table, there are six columns:

• Label needs a string. It is where the action « Goto label » looks for.

• Action: define the type of action

• Ch: define the channel number where the action is applied.

• Parameter: define the parameter of the action if necessary,

• Unit: specify the unit of the parameter (automatically set)

• Comment: define a comment of the current action.

Descriptions of the Actions

Actions

Alpha

Auto

Parameters

Double (x)

Description

Integer from 0 to 255 (n) This value is linked to the feedback coefficient for the pressure regulation. (default value 5)

Send a pressure order in mBar to the specified channel

End

Goto label String (s)

End programme

Manual

Purge off

Double (x)

Go to the line with the s string in the labeled column

The channel is control manually without feedback control. X is equivalent to the % of aperture of the Electrovalve.

Stop purge on channel 1

Purge on

Wait Double (x)

Start purge on channel 1

The program waits for x secondes.

Script Example

Here is an example of a script with the corresponding pressure chart.

5

6

3

4

7

8

9

Step

1

2

Label start

Action Channel Parameter Unit alpha alpha auto wait auto auto wait auto goto label

1

2

1

1

2

2

2

5

5

175

20

210

175

20

140 start mb s mb mb s mb

This is an endless loop generating a 40 seconds period square pressure signal.

20



250

Example of MFCS Mat script for channel 1 and 2

200

150

100

50

Channel 1

Channel 2

0

0 50 100

Time (s)

150 200

Fig. 45—The script above generates this output.

250

Labview

The Labview drivers are in the provided CD.

The Labview library provided is embedded with a set of functions that allows you to control the MFCS in your own Labview program. Here are a few examples of what you can achieve with this library.

Labivew VI

Labview VI mfcs_close.vi

mfcs_data_ chan.vi

Symbol

Handle

Error in

Handle in

Channel data

Error in

Description

Close the MFCS device and the allocated memory.

Error out

Handle out

Channel data

Error out

Get the characteristics of the specified channel:

• Pressure unity (0=no sensor,

1=water inch, 2=PSI)

• Maximum pressure range (in the specified unity)

• Zero pressure value of the sensor (unsigned 12 bits)

• Pressure value (unsigned 12 bits)


21


Labview VI mfcs_get_ purge.vi

mfcs_get_ serial.vi

mfcs_get_ status.vi

mfcs_ initialisation.

vi

Symbol

Handle in

Error in

Handle in

Error in

Handle in

Error in

Handle in

Error in mfcs_read_ chan.vi

Handle in

Channel number

Error in

Error out

Purge ON ?

Handle out

Handle out

Serial Number

Error out

Description

Get status of the purge in channel

1:

• True= Purge ON

• False= Purge OFF

Get the serial number of the MFCS

(0 if no MFCS connected)

Handle out

MFCS Status

Error out

Handle out

Serial number

Error out

Handle out

Pressure

(mBar)

Measure Time

(ms)

Error out

Get the status of the MFCS:

• 0= MFCS is reset. MFCS needs to be manually rearmed

(switch on GREEN button)

• 1= Normal

• 2= Pressure Supply

Overpressure

• 3= MFCS needs to be manually rearmed alter overpressure (switch on GREEN button)

Initialize the MFCS device:

• If the serial number is not specified or equal to 0, the first MFCS device found will be initialized.

• If the serial number is specified, the corresponding

MFCS device is initialized.

Each MFCS has a unique serial number written on the back panel.

• The VI returns the handle and the serial number of the MFCS

(0 if no MFCS found).

Get the pressure value (mBar) and the measure time (ms) of the specified channel (from 1 to 4 or 8).

22



Labview VI mfcs_set_ alpha.vi

mfcs_set_ auto.vi

mfcs_set_ manual.vi

mfcs_set_ purge_off.vi

mfcs_set_ purge_on.vi

mfcs_set_ zero.vi

Symbol

Handle in

(default all)

Alpha (default

Error in

Alpha (default 5)

Handle in

Channel number

Pressure

(mBar)

Error in

Handle in

Channel number

Error in

Handle in

Error in

Handle in

Error in

Handle in

Channel number (0=all)

Zero sensor

Error in

Handle out

Error out

Handle out

Error out

Handle out

Error out

Handle out

Error out

Description

Set the alpha value (default =5) for the specified channel (from 1 to 4 or 8):

• If the specified channel is

0, the same is applied to all channels.

• Alpha is linked to the proportional value of the PID pressure regulation.

Set the regulated pressure value

(mBar) for the specified channel

(from 1 to 4 or 8):

• If the specified channel number is 0, the same pressure is applied to all the channels.

• It is also possible to set the alpha value

Set the electrovalve aperture (%) for the specified channel (from 1 to

4 or 8):

• If the specified channel is

0, the same is applied to all channels.

• The manual control of the electrovalve is not recommended and the output pressure is no longer regulated

Disable purge feature. Channel 1 can be used normally.

Handle out

Error out

Handle out

Error out

Enable purge feature. Channel 1 is directly connected to the pressure supply. Please use with care in order to avoid any damage to your microsystem.

Calibrate the zero pressure value of the specified channel. This value can be estimated with mfcs_data_ chan.vi.


23


Labview Examples

MFCS 8C control

Fig. 46—This VI is a transposition of MFCS control. It integrates MFCS control software’s functions in a Labview environment:

1. Enter the serial number.

2. Calibrate the MFCS, if needed.

3. Set Pressure Order and Alpha (feedback coefficient) in the channels of interests.

4. Press Purge (channel 1 only) to fill or empty your device.

5. Press Stop to stop the pressure.

Control 2 MFCS

Fig. 47—This VI lets you control several MFCS at the same time.

1. Enter the two serial numbers.

2. Select the MFCS of interest with the 1/2 switch of the INPUT box.

3. Set the Channel number, Pressure order and appropriate Alpha (feedback coefficient).

24



4. Press the Stop button to stop pressure.

Calibration

The Calibration process can also be in operated from Labview interface

Fig. 48—Calibration controls

Set Pressure and Alpha–Analog Display

This example allows you to set an order (pressure and feedback coefficient) and then to read the result on an analog curve.

Fig. 49—Set the pressure and feedback coefficients.

Set Pressure–Digital Readout

This example allows you to set a pressure order and monitor the result on a numerical display.

Fig. 50—Set the pressure and watch the numeric output.


25


C++ and VBA

Function Description (preliminary)

Here is a global description of the functions provided with the library.

mfcs_initialisation Initialize the USB for the MFCS. If the serial number is not specified or equal to 0, the first MFCS device found will be initialized.

If the serial Number is specified, the MFCS device with the designated serial number is initialized. Each MFCS has a unique serial number inscribed on the back panel.

mfcs_close mfcs_set_purge_ on

The vi returns the handle and a boolean that confirms that the USB initialized correctly.

Close the MFCS device and the allocated the memory.

Connect the channel 1 output directly to the pressure supply. This function should be used with care, as it can cause damage to the microsystems connected.

mfcs_set_purge_ off mfcs_get_purge mfcs_get_status

Disconnect the channel 1 output from the pressure supply. Channel

1 can be used normally.

Get the status of the purge:

• TRUE = purge ON,

• FALSE = purge OFF

Get the status of the MFCS:

• -1= Trouble in the MFCS connections (USB or electric aperature)

• 0= MFCS is reset. MFCS needs to be manually rearmed

(green switch on the front panel)

• 1= Normal

• 2= Pressure Supply Overpressure

• 3= MFCS needs to be manually rearmed after overpressure

(green switch on the front panel) mfcs_read_chan Get the pressure value (mBar) and the measure time (ms) of the specified channel (from 1 to 4 or 8).

mfcs_data_chan Get the characteristics of the specified channel:

• Pressure Units (0= no captor, 1= inches of water, 2= PSI)

• Maximum Pressure range (in the specified units)

• Zero pressure value of the captor (unsigned 12 bits)

• Pressure value (unsigned 12 bits)

• Chrono value (unsigned 16 bits) mfcs_get_serial Get the Serial Number of the MFCS.

26



mfcs_set_auto mfcs_set_alpha

Set the regulated pressure (mBar) for the specified channel (from

1 to 4 or 8). If the specified channel is 0, the same is applied to all channels.

Set the alpha value (default value =5) for the specified channel

(from 1 to 4 or 8). If the specified channel is 0, the same is applied to all channels. Alpha is linked to the proportional value of the PID.

mfcs_set_manual Set the electrovalve aperature (%) for the specified channel (from

1 to 4 or 8). If the specified channel is 0, the same is applied to all channels. The manual control of the electrovalve is not recommended and the output pressure is no longer regulated.

mfcs_set_zero Save in the EEPROM the zero pressure value of the specified channel.

The following array gives an algorithmic description of the previous functions.

function mfcs_ initialisation mfcs_close mfcs_read mfcs_write return

UL handle

B OK

C error

C error parameter Comment

US serial number Initialise USB connection and look for a MFCS with the specified serial number. handle = 0 if no USB connection

Close USB connection

Read string on the interface

UL handle

UL handle

S string

UL handle

S string

UL handle

Write string on the interface

Open purge on channel 1 mfcs_set_purge_ on mfcs_set_purge_ off

C error

C error mfcs_get_purge C error

UL handle Close purge on channel 1

Get the purge state mfcs_get_status C error

UL handle

PB purge state

UL handle

PC Status

Get MFCS status:

0 if the MFCS is reset

1 if normal

2 if overpressure

3 if MFCS needs to be rearmed.


27


function mfcs_read_chan mfcs_data_chan mfcs_get_serial mfcs_set_auto mfcs_set_alpha mfcs_set_manual C error mfcs_set_zero return

C error

C error

C error

C error

C error

C error

Definition of [C error]:

• - 0 = OK

• - 1 = USB closed

• - 2 = Wrong channel parameter

UL handle

C channel

PF pressure

PUS chrono

UL handle

C channel

PC sensor unit

PUS sensor max

PUS zero

PUS measure

PUS chrono

UL handle

PUS Serial

US handle

C channel

F pressure

UL handle

C channel

C alpha

UL handle

C channel

F EV

UL handle

C channel

US Zero

Comment

Read the pressure value (mBar) of the specified channel with the timing (time unit 25ms).

Read the sensor data:

- sensor unit:

0 = no sensor

1 = "H

2

O (2.4908 mBar)

2 = psi (68.946 mBar)

- full scale in pressure unit

- zero value sensor (U12)

- direct pressure measure (U12)

- chrono (time unit 25ms)

Get the serial number of the

MFCS

Regulate pressure (mBar) on the specified channel. (if 0, the same for all channel)

Set the alpha value (U8). This value is linked to the PID performance. The recommended value is 50 for MFCS devices sold with MFCS_Control V1.05. For a more recent version (V1.06 and

V1.07), the default value is 5 and a preheating of the electro-valves is necessary (45% aperature for

10 min).

Set electro-valve voltage (%) on the specified channel. (If the value is 0, it is set the same for all channels.)

Save Zero sensor value on the firmware. To get this value, use mfcs_data_chan (PUS mesure)

28



symbol bits

UL

US

PUS

S

C

PC

B

PB

F

PF

32

16

32

32

8

32

8

32

32

32

C++

unsigned long

unsigned short

pointer on unsigned short

char[]

unsigned char

unsigned char *

char for boolean result 1 = true, 0 = false

pointer on boolean

float

pointer on float

Labview

(U32)

(U16)

(U16) by address

(abc)

(U8)

(U8) by address

(U8)

(U8) by address

(SGL)

(SGL) by address

VBA

ByVal Long

ByVal Integer

ByRef Integer

ByVal String

ByVal Byte

ByRef Byte

ByVal Byte

ByRef Byte

ByVal Single

ByRef Single

NB:

1) in Visual Basic, all values are signed

2) After calling mfcs_initialisation, a delay (0.5s) must be set before calling other functions,

3) A mfcs_close must be called before leaving the application, to avoid a Windows error.

VBA Declarations Examples

Public Declare Function mfcs_initialisation Lib "d:\mfcs\mfcs_vb.dll"

(ByVal i As Integer) As Long

Public Declare Function mfcs_close Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long) As Byte

Public Declare Function mfcs_read Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal S As String) As Byte

Public Declare Function mfcs_write Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal S As String) As Byte

Public Declare Function mfcs_set_purge_on Lib "d:\mfcs\mfcs_vb.dll"


Public Declare Function mfcs_set_purge_off Lib "d:\mfcs\mfcs_vb.dll"


Public Declare Function mfcs_get_purge Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByRef C As Byte) As Byte

Public Declare Function mfcs_get_status Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByRef C As Byte) As Byte

Public Declare Function mfcs_read_chan Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByRef P As Single,

ByRef Chrono As Integer) As Byte

Public Declare Function mfcs_data_chan Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByRef Su As Byte,

ByRef Sm As Integer, ByRef Zr As Integer, ByRef Ms As Integer,


29


ByRef Chrono As Integer) As Byte

Public Declare Function mfcs_get_serial Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByRef Serial As Integer) As Byte

Public Declare Function mfcs_set_auto Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByVal P As Single) As Byte

Public Declare Function mfcs_set_alpha Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByVal Alpha As Byte) As Byte

Public Declare Function mfcs_set_manual Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByVal Ev As Single) As Byte

Public Declare Function mfcs_set_zero Lib "d:\mfcs\mfcs_vb.dll"

(ByVal H As Long, ByVal Chan As Byte, ByVal Zero As Integer) As Byte

About Output Pressurization

P in

P out

P in

-‐ P out

Atmosphere

Fig. 51—Pressure must be properly equalized.

In order to operate in an optimized range of the pressure full scale, it is recommended to work with differential pressure. Indeed, by pressurizing both input and output of a channel properly, the pressure inside the channel would be equal to the differential of the output and the input pressures.

30



MAINTENANCE

The MFCS is designed as a very robust device for usage in laboratory and industrial environment, so it is easy to maintain. Calibrate it regularly (typically every month) or after the MFCS has been displaced, in order to maintain optimal accuracy of the results and compensate for offset drift of the pressure sensors.

The housing can be cleaned with a soft tissue moistened with iso-propanol or windowcleaning products.

Avoid aggressive organic solvents as acetone or chloroform or abrasive cleaning products.


31


ACCESSORIES

Designation

USB Cable

CD Software

Reference and Supplier

User manual

Blue tubing (OD=1/32’’, ID=250µm)

FEP tubing (OD=1/16’’, ID=800µm)

Upchurch Scientific : 1581

Fisher : A28556

Glass capillary (OD=360µm’, ID=100µm) Polymicro technologies : TPS100375

Green Sleeves (1/16˝ to 360µm) Upchurch Scientific : F-242X

Green Sleeves (1/16˝ to 1/32˝)

10-32 Peek Fitting Nuts soft tubing (1x3mm)

Micrew reservoir 1.5 mL

Upchurch Scientific : F-247X

Upchurch Scientific : F-120

Fisher : A31309

Fisher : W14432

32



SPECIFICATIONS

MFCS 25 mBar

Characteristics

Input pressure range

Output pressure precision

Min. output pressure step

Max. output pressure -

-

Operation temperature range 5

Input voltage range 23

-

-

Min.

Typ.

500 600 mbar

<2.5 % -

23

25

25

24

-

-

Max.

40

25

Unit full scale

µbar mbar

°C

V

Comment

Better if calibrated

(see Quick start)

Weight

Power consumption -

1.9

-

2.25

kg

<16 W

Depends on model

MFCS 70 mBar

Characteristics




Max. output pressure



Weight 1.9

-

-

-

-

Min.

Typ.

500

<2.5 % -

Max.

Unit

600 mbar full scale

Comment


(see Quick start)

63

69 -

µbar mbar

-

25

24

40

25

°C

V

2.25

kg Depends on model

Power consumption <16 W


33


MFCS 350 mBar

Characteristics




Max. output pressure



Weight 1.9

-

-

-

-

Min.

Typ.

800

<2.5 % -

Max.

Unit

900 mbar

Comment full scale Better if calibrated

(see Quick start)

0.32

343 -

mbar mbar

-

25

24

40

25

2.25

°C

V kg Depends on model


MFCS 1000 mBar

Characteristics


Output pressure precision -

-

Min.

Typ.

1.3

<2.5 % -

Max.

1.4


Max. output pressure -

-



Weight 1.9

-

0.95

1033

25

24

-

-

40

25

2.25

Unit bar full scale mbar mbar

°C

V kg

Comment


(see Quick start)

Depends on model


34



APPENDIX A

Response and Stabilization Time

Here are the graphic definitions of response time and stabilization time.

Pressure

5%

StabilizationTime

100%

Response Time

Fig. 52—On this graph you can see when the system begins to respond and when it actually stabilizes.

Ti me

Unit Conversion Table

value (

↓) = factor xunit (

→)

1 kPa

1 bar

1 psi

1 inch H

2

O kPa

1

100

6.895

0.249

bar

0.01

1

68.95x10-3

2.49x10-3

Example: 10 kPa = 10 kPa x 0.01 bar/kPa = 0.1 bar psi

0.145

14.5

1

3.612x10-2 inch H2O

4.016

401.6

27.68

1


35


Hydrodynamic Resistance of Rectangular Channels and

Networks

Pressure difference (

Δp), the volume flow rate (Q), or the averaged velocity (u) and the friction coefficient (C) are related with channel dimensions (a and b) when a/b>>1, channel length (L) and viscosity (µ). (µ= 9.5 x10

-4 Pa s for H

2

O at 25°C)

The relation between the friction C and the aspect ratio a/b can be calculated [Stone,

Stroock, Ajdari, Ann. Rev. Fluid. Mech., 2004]: with

Fig. 53—This graph shows the friction coefficient as a function of the aspect ratio of the channel and can be used to estimate the flow rate due to a given pressure difference.

Typical values are: x=1

⇒ C=0.03512; x=2 ⇒ C=0.05708; x=10 ⇒ C=0.07688.

Example: A channel of 10x100µm with a length of 10mm contains 0.01µl. Applying a pressure difference of 10Pa (=100 µBar) gives a volume flow rate of about Q=0.0005µl/

36



min and an averaged flow velocity of u = 5µm/min. A pressure of 100,000 Pa (=1 bar) is

10,000 times higher, thus the flow rate and velocity are also 10,000 times increased.

Since Ohm's law also applies to flow of other particles than electrons (for example, water), we can transfer the formulas.

For a single channel, we have for the volume flow (Q) as a function of the externally applied pressure difference (p) and the resistance (R): Q=p /R, Q=abu.

The pressure (pc) at an arbitrary position in a single channel with partial resistances (R1 and R2) of the two halves of the channel is:

The total resistance is R=R1+R2, the flow yields Q=(p1−pc)/R1, R2 is equivalent.

If the two parts are of equal resistance (equal length and diameter), we find the well known average value: pc=(p1+p2)/2

For three channels (p1, p2, p3 and R1, R2, R3) joining in one point with pressure (pc) we find using the continuity equation (the sum over all Qs going into one knot vanishes)

The corresponding flow in channel 1 (as an example) can be obtained with Ohm's law:

Q1=(p1−pc)/R1

The other values are equivalent.

To obtain the corresponding formulas for n channels joining in one knot, the latter formula can be generalized:

More complex geometries can be calculated using well-known methods in analogy to electrical resistor networks (pressure is equivalent to the electric potential, flow is equivalent to the current, and flow resistance of a channel plays the same role as the

Ohm's resistance).


37


Trace and Log Flle Formats

MFCScontrol allows a complete real time recording of all settings and measured pressure values during operation.

11.07.2005 17:39:03 MFCS S/N:0003 V:000.011

15885 18.424 0.426 5.146 20.560

15886 18.424 0.426 5.100 20.477

15887 18.386 0.395 5.100 20.454

15888 18.371 0.426 5.123 20.583

15889 18.485 0.395 5.100 20.583

15890 18.462 0.426 5.100 20.500

15891 18.402 0.426 5.146 20.500

15892 18.333 0.395 5.123 ...

Fig. 54—Example of a trace file

The trace file format consists of a header line and a data block. The header line is composed of the starting date and time, serial number of the connected unit and version number of the MFCScontrol software. The data block is composed of lines carrying a time stamp (absolute time and the internal step number) and the 4 (8) pressure values. '#N/A' means information was lost (for example, transient transmission failure). When using this option, avoid the creation of oversized data files. Adjust the storage frequency, as necessary. (See the pull down menus.)

11.07.2005 17:27:38 --BEGIN OF LOG--

11.07.2005 17:27:43 AUTO. Chan. 1 : 2196

11.07.2005 17:27:43 AUTO. Chan. 1 : 2221

11.07.2005 17:27:43 AUTO. Chan. 1 : 2246

11.07.2005 17:27:43 AUTO. Chan. 1 : 2283

11.07.2005 17:27:43 AUTO. Chan. 1 : 2332

11.07.2005 17:27:43 AUTO. Chan. 1 : 2381

11.07.2005 17:27:43 AUTO. Chan. 1 : 2406

11.07.2005 17:27:45 AUTO. Chan. 1 : 2715

11.07.2005 17:27:45 AUTO. Chan. 1 : 2727

11.07.2005 17:27:46 AUTO. Chan. 1 : 2739

11.07.2005 17:27:46 AUTO. Chan. 1 : 2739

11.07.2005 17:27:46 AUTO. Chan. 1 : 2739

11.07.2005 17:39:27 --END OF LOG--

Fig. 55—Example of a Log file

Command

ALPHA Chan. X : YYYYY

AUTO Chan. X :YYYYY

--BEGIN OF LOG--

--END OF LOG--

Order set  value to YYYYY in Channel X set value YYYYY in Channel X in feed back mode start logging stop logging

38



Command

MANUAL Chan. X : YYYYY

Order set value YYYYY in Channel X in manual mode

PURGE OFF

PURGE ON

USB OFF

USB ON

ZERO Chan. X : YYYYY open purge valve close purge valve close USB channel open USB channel set zero value YYYYY on channel X

Fig. 56—Commands sent from the computer to the MFCS

Order mfcs exceeding input pressure mfcs operating mfcs purge off

MFCS S/N:---- V:---mfcs purge on mfcs reset detected

Message input pressure exceeds threshold value system is operating normally purge is switched off comprising serial and version number purge is switched on system has realized activation of reset signal (button, processor reset line)

Fig. 57—Commands sent from the MFCS to the computer.


39


WARRANTY

WPI (World Precision Instruments, Inc.) warrants to the original purchaser that this equipment, including its components and parts, shall be free from defects in material and workmanship for a period of one year* from the date of receipt. WPI’s obligation under this warranty shall be limited to repair or replacement, at

WPI’s option, of the equipment or defective components or parts upon receipt thereof f.o.b. WPI, Sarasota,

Florida U.S.A. Return of a repaired instrument shall be f.o.b. Sarasota.

The above warranty is contingent upon normal usage and does not cover products which have been modified without WPI’s approval or which have been subjected to unusual physical or electrical stress or on which the original identification marks have been removed or altered. The above warranty will not apply if adjustment, repair or parts replacement is required because of accident, neglect, misuse, failure of electric power, air conditioning, humidity control, or causes other than normal and ordinary usage.

To the extent that any of its equipment is furnished by a manufacturer other than WPI, the foregoing warranty shall be applicable only to the extent of the warranty furnished by such other manufacturer. This warranty will not apply to appearance terms, such as knobs, handles, dials or the like.

WPI makes no warranty of any kind, express or implied or statutory, including without limitation any warranties of merchantability and/or fitness for a particular purpose. WPI shall not be liable for any damages, whether direct, indirect, special or consequential arising from a failure of this product to operate in the manner desired by the user. WPI shall not be liable for any damage to data or property that may be caused directly or indirectly by use of this product.

Claims and Returns

• Inspect all shipments upon receipt. Missing cartons or obvious damage to cartons should be noted on the delivery receipt before signing. Concealed loss or damage should be reported at once to the carrier and an inspection requested. All claims for shortage or damage must be made within 10 days after receipt of shipment. Claims for lost shipments must be made within 30 days of invoice or other notification of shipment. Please save damaged or pilfered cartons until claim settles. In some instances, photographic documentation may be required. Some items are time sensitive; WPI assumes no extended warranty or any liability for use beyond the date specified on the container.

• WPI cannot be held responsible for items damaged in shipment en route to us. Please enclose merchandise in its original shipping container to avoid damage from handling. We recommend that you insure merchandise when shipping. The customer is responsible for paying shipping expenses including adequate insurance on all items returned.

• Do not return any goods to WPI without obtaining prior approval and instructions (RMA#) from our returns department. Goods returned unauthorized or by collect freight may be refused. The RMA# must be clearly displayed on the outside of the box, or the package will not be accepted. Please contact the RMA department for a request form.

• Goods returned for repair must be reasonably clean and free of hazardous materials.

• A handling fee is charged for goods returned for exchange or credit. This fee may add up to 25% of the sale price depending on the condition of the item. Goods ordered in error are also subject to the handling fee.

• Equipment which was built as a special order cannot be returned.

• Always refer to the RMA# when contacting WPI to obtain a status of your returned item.

• For any other issues regarding a claim or return, please contact the RMA department

Warning: This equipment is not designed or intended for use on humans.

* Electrodes, batteries and other consumable parts are warranted for 30 days only from the date on which the customer receives these items.

World Precision Instruments, Inc.

international Trade Center, 175 Sarasota Center Blvd., Sarasota FL 34240-9258

Tel: 941-371-1003 • Fax: 941-377-5428 • E-mail: [email protected]

UK: Astonbury Farm Business Centre • Aston, Stevenage, Hertfordshire SG2 7EG • Tel: 01438-880025 • Fax: 01438-880026 • E-mail: [email protected]

40


China & Hong Kong: Rm 20a, No8 Dong Fang Rd., Lu Jia Zui Financial District, shanghaai PRC • Tel: +86 688 85517 • E-mail: [email protected]

WPI FL-MFCS Microfluidics Control System Instruction manual

INSTRUCTION MANUAL

Serial No._____________________

FL-MFCS

Microfluidics Control System

World Precision Instruments

Fluiwell

To your application

Soft

Tubes

Reservoirs

Parts List

FEP Caps

Fluiwell Reservoirs

Unpacking

Rear View

Pressure Inlet

USB

Power Supply

On / Off Switch

LCD Pannel

Front View

Green Button

Red Button

Pressure outlet

Required Materials

Setup

Fig. 16—MFCS software welcome screen

Starting the MFCS

✔

✔

Purging

Controlling Pressure in the Channels

Tab Configurations

Saving Curves

Coupling

Manual/Auto Modes

Feedback Coefficient

MFCS Mat (Scripting Software)

General Description

Description of the Table

Descriptions of the Actions

Script Example

Labview

Labivew VI

Labview Examples

MFCS 8C control

Control 2 MFCS

Calibration

Set Pressure and Alpha–Analog Display

Set Pressure–Digital Readout

C++ and VBA

Function Description (preliminary)

VBA Declarations Examples

About Output Pressurization

Designation

Reference and Supplier

MFCS 25 mBar

MFCS 70 mBar

MFCS 350 mBar

MFCS 1000 mBar

Response and Stabilization Time

Unit Conversion Table

Hydrodynamic Resistance of Rectangular Channels and

Networks

Trace and Log Flle Formats

Claims and Returns

World Precision Instruments, Inc.

international Trade Center, 175 Sarasota Center Blvd., Sarasota FL 34240-9258

Tel: 941-371-1003 • Fax: 941-377-5428 • E-mail: [email protected]

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