2020/10/23 by Brinker, Manuel, Dittrich, Guido, Richert, Claudia +5
Physics and Astronomy · #Chemie #Physics - Chemical Physics #Physics - Materials Science #Physics - Mesoscopic Systems and Quantum Hall Effect #Physics - Soft Condensed Matter #Physik #physics.app-ph
paper · doi:10.15480/882.3001
The absence of piezoelectricity in silicon makes direct electro-mechanical applications of this mainstream semiconductor impossible. Integrated electrical control of the silicon mechanics, however, would open up new perspectives for on-chip actuorics. Here, we combine wafer-scale nanoporosity in single-crystalline silicon with polymerization of an artificial muscle material inside pore space to synthesize a composite that shows macroscopic electrostrain in aqueous electrolyte. The voltage-strain coupling is 3 orders of magnitude larger than the best-performing ceramics in terms of piezoelectric actuation. We trace this huge electroactuation to the concerted action of 100 billions of nanopores per square centimetre cross-section and to potential-dependent pressures of up to 150 atmospheres at the single-pore scale. The exceptionally small operation voltages (0.4-0.9 V) along with the sustainable and biocompatible base materials make this hybrid promising for bio-actuator applications.