3D stepped electrodes on a flexible substrate with permanently bonded poly(dimethylsiloxane) channels for moving microfluid

Interdigitated microelectrode arrays have been exploited to move electrolyte via ac electro-osmosis. The performance of three dimensional (3D) stepped electrodes has been shown to exceed that of planar electrodes. However, to date all prototypes described have been based on solid silicon or glass substrates, limiting the usage of such devices. This report, to our best knowledge, is the first to describe a 3D stepped microelectrode array on a flexible Kapton^® substrate. The Kapton surface was modified to make it capable of bonding with poly(dimethylsiloxane) microchannels. The metal electrode was patterned by wet etching, a simpler process than previous approaches. Results of bonding, bending, and fluidic testing are reported. The frequency response obtained using deionized water showed maximum velocities of approximately 370 and 180 μm/s at 5Vpp for testing with a flat and bent substrate, respectively.