%0 journal article
%@ 2375-2548
%A Brinker, M., Dittrich, G., Richert, C., Lakner, P., Krekeler, T., Keller, T., Huber, N., Huber, P.

%D 2020
%J Science Advances
%N 40
%P eaba1483 
%R doi:10.1126/sciadv.aba1483
%T Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material
%U https://doi.org/10.1126/sciadv.aba1483
40 
%X The absence of piezoelectricity in silicon makes direct electromechanical 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 three 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 centimeter cross section and to potential-dependent pressures of up to 150 atmospheres at the single-pore scale. The exceptionally small operation voltages (0.4 to 0.9 volts), along with the sustainable and biocompatible base materials, make this hybrid promising for bioactuator applications.