In situ electrochemical control of electroactive polymer films on a CMOS chip

The paper reports, for the first time, an integrated potentiostat for driving electrochemical actuation reactions on a CMOS chip. The integrated microsystem comprised on-chip working, counter, and quasi-reference electrodes fabricated on top of the necessary control circuitry. To demonstrate its capability, the potentiostat chip was used to electrodeposit films of polypyrrole/dodecylbenzenesulfonate, PPy(DBS), in situ onto the working electrodes. It was also used to cycle PPy(DBS) films between the fully oxidized and fully reduced states. This was confirmed by video recordings of the distinctive electrochromic changes, as well as by the shapes of the cyclic voltammograms. Both showed good repeatability. The demonstrated approach of integrating driver circuitry along with actuation electrodes on a common CMOS substrate eliminates the need for an external potentiostat instrument, and can be widely employed for the fabrication and control of electrochemical microactuators in integrated lab-on-a-chip systems.