To further elucidate the interaction between electro-osmotic flow and surface charge, we are building a nanochannel with an embedded electrode. Such a system can directly change the surface charge by applying voltage. This novel technique provides several advantages, including the use of only one electrolyte solution, the ability to directly modulate the electric double layer (EDL) by applying potentials on the embedded electrodes, and the production of predictable sample plugs. In order to adjust the thickness of the EDL without any chemical reaction, the liquid solution and the metal will be isolated. The wet etching is used before the metal deposition. To isolate the metal from the liquid, the sputtering silica covers the etched area. A nanochannel on the embedded electrode is etched by the dry etching technology. The CNC driller is used to create an access for the channel. The two silica wafers will be bonded together in the final process which requires a uniform surface. This device can contribute to further understanding of nanofluidic electrokinetic systems and we believe that it can lead to breakthroughs for complex nanofluidic electrokinetic systems.
Reference:
[1] Boden, S., Karam, P., Schmidt, A., & Pennathur, S. (2017). A process to fabricate fused silica nanofluidic devices with embedded electrodes using an optimized room temperature bonding technique. Applied Physics Letters, 110(18), 181605.