I have recently take over the DropBot setup here in York, UK and despite having manufactured nice devices and having a fully functional setup, I’m still struggling to get much droplet actuation going. Being fairly new to DMF I wanted to walk you through my setup and maybe someone can point out any glaring mistakes I might be making:
The DropBot system is built using the instructions on the DropBot wiki and are as far as I can tell, fully functional. I’ve attached Device load calibration and High-voltage reference loads results. I have also attached a few pictures of the setup, where as far as I can tell, everything is connected correctly.
The devices are fabricated in-house by me using chromium electrodes made by wet-etching in a standard clean-room photolithographic method (using the “SCI-BOTS 90 pin-array v3” mask design). The connector and ground pads are then masked off and 8µm Parylene-C is deposited. The pads are unmasked and finally I apply 100nm Teflon (AF1600). For the top layer I’m using commercially coated ITO-glass, also coated with Teflon.
As for putting everything together I’ve struggled to find clear instructions, but I think I’ve managed to piece it all together from various post in this group. I use two layers of double sided tape (Scotch) to create ~140µm spacing between the two plates and tinfoil to connect the top electrode. I’ve attached a photo (ignore the gold, it’s now chromium). I’ve attached channel impedance scan for a particular device.
For testing purposes I’ve simply been using DI water with 2% (w/w) Tween20.
Loading the reservoirs usually goes quite well and the liquid stays nicely on the electrode. When I start actuating other electrodes very little happens and where I’m currently stuck.
Like I said, I’m quite new to DMF so anyone has any useful inputs at all I would be very grateful. Thanks in advance,
channel-impedances chrome etch 2.pdf (41.8 KB)