Download Instructions OpenDrop Prototype – Digital Microfludics

Instructions OpenDrop Prototype – Digital Microfludics Plattform
OpenDrop is a new design for an open source digital microfludics platform for research purposes.
The device uses recent electro-wetting technology to control small droplets of liquids. Potential
applications are lab on a chip devices for automating processes of digital biology.
*** DISCLAIMER ***
This is a prototype device for research purpose. The circuit generates voltages of up to 280 VDC.
You the user, bear the responsibility for your own safety and safety of others in using this device.
IN NO EVENT SHALL WE BE LIABLE FOR ANY DAMAGES OR LOSSES OF ANY KIND. Be sure that you
understood the basic circuit concepts and have the required knowledge to operate it.
Removable Droplet Carrier
The OpenDrop devices is based on 8×8 electrode array with 4 reservoirs integrated into the
printed circuit board. The liquids stay on a thin, hydrophobic foil attached to the droplet carrier.
The foil (5-7 um thick) should lay flat on the electrode array with no air gap in between. A thin film
of mineral oil can be applied to the electrodes before applying the foil. The electrodes are gold
coted and not isolated. Make sure that no conductive liquids come in contact with the electrodes
or flow into the electronic circuit as this may cause short circuits.
A good electro-wetting foil for the device is still under development. Current results are based on a
Saran Wrap wrap foil attached to the bottom of the carrier through double sided tape and coated
with Rain-X water repellent to make the surface hydrophobic.
Programming
The OpenDrop is based on the Arduino UNO micro-controller board. The electrodes are addressed
in a x-y coordinate system (see picture below). A sample code with the instruction “SetFluxel(x,y);”
to activate one single electrode can be found on the OpenDrop website.
Instruction on how to install the Arduino programming tool and how to use it can be found here:
http://arduino.cc/en/Guide/HomePage
Powering
To power the device use a standard Arduino power adapter rated at 12V DC, 250mA (min) and
plug it into the power plug of the Arduino.
To switch the high voltage supply to the electrodes use the toggle switch on the top left. The up
position (1) is on. The red LED (HV) should be turned on. Be aware that the power converter is
always on when as long as the device is plugged in. Make sure that the high voltage is switched of
before manipulating the device.
Adjust the voltage level using the trimmer potentiometer (blue). Turning the trim-pot
counterclockwise increases the voltage.
For more information including schematics, circuit board design and general updates see:
http://www.gaudi.ch/GaudiLabs/?page_id=392
All OpenDrop software, design files and instructions are licensed under the GNU GPLv3 License.