Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material

The absence of piezoelectricity in silicon can lead to direct electromechanical applications of the mainstream semiconductor material. The integrated electrical control of silicon mechanics can open new perspectives for on-chip actuators. In a new report, Manuel Brinker and a research team in physics, materials, microscopy and hybrid nanostructures in Germany, combined wafer-scale nanoporosity in single-crystalline silicon to synthesize a composite demonstrating macroscopic electrostrain in aqueous electrolytes. The voltage-strain coupling was three-orders of magnitude larger than the best performing ceramics. Brinker et al. traced the electro-actuation to the concerted action of a 100 billion nanopores-per-square-centimeter cross-section and obtained exceptionally small operation voltages (0.4 to 0.9 volts) alongside sustainable and biocompatible base materials for biohybrid materials with promising bioactuator applications. The work is now published on Science Advances.