Dial-A-Wave

Dial-A-Wave, or "DAW" as commonly referred around the lab, is a system of hardware, software and microfluidic devices that allows for time-lapse microscopy of single cells in a time-varying extracellular environment. A very thorough overview on the basic concepts of microfluidics has been publish in a book chapter "Microfluidics for Synthetic Biology: From Design to Execution".[1] Use this article to track updates and changes to the system.

Overview

The system is composed of a microfluidic device (figure above) and a mechanical setup for changing the pressures applied to the microfluidic device. Using microfluidic devices we are able to trap and maintain viable cells, while precisely controlling the external environment variables, such as temperature, humidity and gas composition. To allow for time-dependent extracellular concentrations of a specific chemical (i.e. inducers, antibiotics, dyes...), the microfluidic devices is designed to included a fluidic mixer. The mixer has two incoming ports that connect to reservoirs with (1: media, 2: media + inducers of certain concentration). By varying the relative pressures of these two reservoirs, the ratio of the two fluids going out of the middle channel changes. By mirroring the pressure change of one of the reservoirs with an equal but opposite change in the second reservoir, the total pressure through the mixer remains constant. This maintains that the total flow through the microfluidic device is constant throughout the experiment. Each port is connected to a syringe via flexible tubing and metal pins. By changing the height of the syringes we can achieve different pressures at various ports. To achieve dynamic pressure changes we use a mechanical system that controls the height of the syringes. Refer to Hardware section.

Hardware

Original DAW (v1)

The first system uses two vertically mounter linear actuators. The syringes with media are attached to the carriage of each actuator and the positions of the carriages are controlled by a custom LabVIEW software package. This setup allows for independent positioning of each syringe; each linear actuator has a range of 800 mm with a 0.01 mm step size. Since the actuators have built-in optical encoders, the position is accurate and reproducible. Each actuator has a dedicated controller, which connects to a hub that communicates with the computer via MODBUS protocol. Both actuators are powered with a single power supply. It is possible to increase the total number of actuators to 16 without significant modifications to hardware or LabVIEW software.

The only disadvantage of this system is the total cost per setup, which can be around $4000-$5000. Assembling the system is relatively easy, with no machining or custom parts. If money is not a problem, this is a better system in terms of ease of installation and accuracy.

Equipment
Qty
Part No.
Vendor
Linear actuators: fast speed, 800mm travel length
2
RCP2-SA7C-I-56P-16-800-P1-M-BE
Valin Corp.
Controller
2
RPCON-56P
Valin Corp.
Communication gateway module
1
RGW-SIO
Valin Corp.
Serial communication cable
1
CB-RCA-SIO-050
Valin Corp.
USB adapter
1
RCB-CV-USB
Valin Corp.
USB cable
1
CB-SEL-USB010
Valin Corp.
24V DC power supply
1
OMRON-S8VS-06024
Valin Corp.
AC power cable
1
70355K34
McMaster-Carr
Syringe holders
1 pkg
7565K51
McMaster-Carr
Screws for syringe holders (M3, 8mm)
1 pkg
96477A162
McMaster-Carr

Installation Instructions

Design Files

Poor Man's DAW (v2)

Since the total pressure at the fluidic mixer stays constant throughout the experiment, this means that movement of one of the syringes must be mirrored by the other syringe in the opposite direction. Due to this constraint we can remove one of the actuators from the Original DAW (v1) and replace it with a linear guide and carriage system. By connecting the carriage on the linear guide to the carriage on the linear actuator with a system of wire rope and pulleys, we can achieve the same effect. This brings down the total part cost, but increases the complexity of the system. When putting the system together it is important to make sure that the wire rope stays in the same plane. Since we are using the same actuators, there is no modification necessary to the LabVIEW software.

Equipment
Qty
Part No.
Vendor
Linear actuators: fast speed, 800mm travel length
1
RCP2-SA7C-I-56P-16-800-P1-M-BE
Valin Corp.
Controller
1
RPCON-56P
Valin Corp.
Communication gateway module
1
RGW-SIO
Valin Corp.
Serial communication cable
1
CB-RCA-SIO-050
Valin Corp.
USB adapter
1
RCB-CV-USB
Valin Corp.
USB cable
1
CB-SEL-USB010
Valin Corp.
24V DC power supply
1
OMRON-S8VS-06024
Valin Corp.
AC power cable
1
70355K34
McMaster-Carr
Syringe holders
1 pkg
7565K51
McMaster-Carr
Screws for syringe holders (M5, 8mm)
1 pkg
96477A162
McMaster-Carr
Linear guide 1000 mm
1
TS-01-15
Igus, Inc.
Carriage
1
TW-01-15
Igus, Inc.
SS screws for linear guide (8-32 x 1 1/4 in)
1 pkg
92185A201
McMaster-Carr
8-32 Hex nut
1 pkg
90257A009
McMaster-Carr
No 8. flat washer
1 pkg
92141A009
McMaster-Carr
Wire rope connection to actuator car
Ball joint rod end
1
6275K52
McMaster-Carr
Wire rope end stud
1
3475T15
McMaster-Carr
Thread adapter
1
92499A487
McMaster-Carr
1/2 inch Steel block (cut to 3x3 inch blocks)
1
8151K311
McMaster-Carr
Wire rope
7ft
8923T31
McMaster-Carr
Rope clamp
2
3677T51
McMaster-Carr
Pulley Connection to wood
Pulley
8
3434T14
McMaster-Carr
Shoulder screw
8
93996A714
McMaster-Carr
Weld nut
8
90611A250
McMaster-Carr
No. 2 wood screw
24
90011A081
McMaster-Carr
For offset of pulley base to be inline with carriages
Weld nut
12
90611A450
McMaster-Carr
Shoulder screw
4
91264A650
McMaster-Carr
Sleave bearing
4
6389K622
McMaster-Carr
4 in threaded rod
4
98750A070
McMaster-Carr
Locknut
4
93298A130
McMaster-Carr
No. 6 wood screw
24
90011A151
McMaster-Carr
Particle board (MDF 5/8 inch thickness)
2
cut to size
Home Depot
For offset of linear guide base to be inline with carriage
Shoulder screw
8
91259A720
McMaster-Carr
Sleave bearing
8
6389K622
McMaster-Carr
3 in threaded rod
12
98750A066
McMaster-Carr
Locknut
12
93298A130
McMaster-Carr
Particle board (MDF 5/8 inch thickness)
8
cut to size
Home Depot

Design Files

Grad Student DAW (v3)

The most recent version of the system moves away from the use of linear actuators. To achieve motion, the system relies on a single stepper motor with timing pulleys and a belt drive. The main reason for switching to the new design is the significant reduction in cost: a single system should cost about $500. However, there are a number of disadvantages: first, the setup does not include an optical encoder, so the position relies on the motor's internal counter which can be inaccurate in some circumstances; second, this design requires some simple assembly and manufacturing. We have tested the system, and the absence of the optical encoder is not that significant. The only issue that can arise is when the motion of the carriages is physically obstructed. Since the step size of the motor is only 0.9 degrees, an error of a few steps will not cause the system to fail.

Equipment
Qty
Part No.
Vendor
Motor and controller
NEMA-23 Bipolar 50mm Stepper Motor
1
3308
Phidgets
Power supply 12VDC 2.0A -US
1
3024
Phidgets
Bipolar motor control board
1
1063
Phidgets
Linear guide and carriage
T guide rail (1000 mm)
2
TS-01-15
Igus, Inc.
T carriage
2
TW-01-15
Igus, Inc.
Nuts and bolts
SS 8-32 x 5/8 (Motor housing)
4
92185A196
McMaster-Carr
SS 8-32 x 1 1/4 (Linear guide)
10
92185A201
McMaster-Carr
No. 8 flat washer
14
92141A009
McMaster-Carr
8-32 Hex Nut
14
90257A009
McMaster-Carr
SS 1/4-20 x 1 1/2 (Main housing)
4
92185A546
McMaster-Carr
1/4 Flat Washer
4
90313A203
McMaster-Carr
1/4-20 Hex SS nut
4
94804A029
McMaster-Carr
M3x12mm screw
4
92290A117
McMaster-Carr
Nylon washer #8
2
93785A400
McMaster-Carr
5-40 Hex Nut
1
91841A006
McMaster-Carr
M3x8mm screw
3
92290A113
McMaster-Carr
M5x8mm screw
5
91420A318
McMaster-Carr
M5x20mm screw
8
91420A328
McMaster-Carr
Pulleys and Belts
0.08 pitch, 1/4in wide, open ended neoprene belt
7ft
A 6Z16-C025
SPD-SI
Mount Bearing on Hardened Shaft
1
S99NH2-BN0408
SPD-SI
0.08(MXL) pitch, 18 teeth, Aluminum alloy timing pulley
2
A 6A16-018DF2508
SPD-SI
Polycarbonate belt clamp
2
A 6M16M080
SPD-SI
Custom Parts
Motor housing (1/4in acrylic)
1
refer to design files
local machine shop or contact our lab
Board housing (1/4in acrylic)
1
refer to design files
local machine shop or contact our lab
Alignment guide (1/4in acrylic) (optional)
1
refer to design files
local machine shop or contact our lab
Dowel pin (1.3in length with 0.4in 5-40 thread; 1/8in diam)
1

local machine shop or contact our lab
Steel block (1/2in thick)
2
refer to design files
local machine shop or contact our lab
Adjustable belt/carriage connection
1
refer to assembly instructions
local machine shop or contact our lab
Reusable equipment
0.124 reamer
1
3087A51
McMaster-Carr
#40 Drill
1
30585A54
McMaster-Carr
M3 Tap
1
8302A12
McMaster-Carr
5-40 Die
1
2576A135
McMaster-Carr
Die holder
1
25565A19
McMaster-Carr
Other equipment
Syringe holders
1 pkg
7565K51
McMaster-Carr
Baseboard (pressed wood composite, 49" H x 9" W x 5/8" thick)
1


Optional: Meterstick (max. width 1 1/8") and fasteners
1


Design Files

Software

LabVIEW (version 1 and 2 only)

Depending on the hardware setup you have chosen (version 1 or 2), you will need to use different software packages.

For version 1, it is necessary to use the software called "DialAWave version 6 Last Update 02_20_09".

You can download it directly - DialAWave version 6 Last Update 02_20_09 or download from our Software Repository.

This is not a standalone package, you need to have National Instruments LabVIEW 7.1 or higher.

To install and run the software follow the prompts outlined in the v1 DAW Installation Instructions

Please see the User Manual for DAW v6 Software for more information.

If you are using the "Poor Man's DAW(v2)" then it is necessary to use the software called "DialAWave version 9 Last Update 11_14_11"

You can download it directly - DialAWave version 9 Last Update 11_14_11 or download from our Software Repository.

Java (version 1, 2 and 3)

Version 2

Now the linear actuators can also be run by the java software. The user interface is identical between the two programs. So, the following link is only for Version 2, that is the version that uses IAI Linear actuators

Latest compiled version - standalone java version 2 software

Here is the source - full project

Version 3

The Java version of the software was written specifically for the new hardware setup (Grad Student DAW v3). The overall layout of the software is very similar to the LabVIEW version.

You can download the latest compiled version - standalone software

If you would like to work on the software, which we highly encourage, download the complete NetBeans project - full project or download from our Software Repository.

Our Java software will require you to download OS specific drivers for the controller from the Phidgets website.

The software has been tested on Windows 7 and Mac OS 10.5.8.

Due to recent changes in the Phidgets supplied drivers, we are providing the older version of drivers that work with our software, choose your OS below:

  1. Windows (32-bit) - driver date 2014/02/27
  2. Windows (64-bit) - driver date 2014/02/27
  3. Mac OS X - driver date 2011/11/03

For older versions, see the Older Software page.

Microfluidic Devices

The paper includes a very thorough description on how to design microfluidic devices. Here you can download the actual design and printing files for the device described in the paper.

  1. Design file (Autocad 2010 DWG) - design_file
  2. Printing file (Autocad 2010 DWG) - print_file
  3. Fabrication parameters for making the wafers in a cleanroom environment (Excel file) - fabrication paramters
    • Masks should be printed: Emulsion Up, Negative Image at 20,000 dpi

General Lab Equipment and Supplies

Equipment Qty Part No. Vendor
Vacuum Pump RV8 1 A65401906 Edwards
Desiccators 2 08-642-5 Fisher Scientific
Isotemp Oven 1 506G Fisher Scientific
Silicone Elastomer kit 1 Sylgard 184 Dow Corning
Release agent(*note) 1 T2492 UCT
Aluminum foil      
UVO cleaner (bonder) 1 Model No. 42 Jelight Company Inc.
Flowmeter (oxygen) 1 FR4A37 Key Instruments
Biopsy punch Harris Uni-Core 0.5 mm 1 15071 Ted Pella, Inc.
Cover slips No 1 1/2, size: 24x40mm, thickness 0.16-0.19mm 12-530F Fisher Scientific
Compressed oxygen for bonder 1 medial grade  

*note - release agent's chemical name: (TRIDECAFLUORO-1,1,2,2-TETRAHYDROOCTYL)-1-TRICHLOROSILANE


M.S. Ferry, I.A. Razinkov, J. Hasty (2011) Chapter Fourteen - Microfluidics for Synthetic Biology: From Design to Execution Methods in Enzymology (497): 295-372