Impedance spectroscopy on stretchable microelectrode arrays

We are reporting on the fabrication and electrical characterization of stretchable polydimethylsiloxane (PDMS) based microelectrode arrays for recording of neuronal action potentials. Electrodes are immersed in phosphate buffered saline solution. Their electrical impedance spectra are recorded as a function of uniaxial macroscopic strain applied using a custom built automated stretcher. We propose a model to account for the physical phenomena responsible for electrical conduction in the bulk electrode and at the metal–electrolyte interface. Electrodes with active area dimensions of $100×140μm2$ maintain an impedance of approximately $1MΩ$ at 1 kHz when cycled to 20% strain.