Brinker Manuel, Dittrich Guido, Richert Claudia, Lakner Pirmin, Krekeler Tobias, Keller Thomas F, Huber Norbert, Huber Patrick
Physics of Materials and High-Resolution X-Ray Analytics of the Structural Dynamics and Function of Matter, Hamburg University of Technology TUHH, 21073 Hamburg, Germany.
Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht, Germany.
Sci Adv. 2020 Sep 30;6(40). doi: 10.1126/sciadv.aba1483. Print 2020 Sep.
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.
硅中不存在压电性，这使得这种主流半导体无法直接应用于机电领域。然而，对硅力学进行集成电气控制将为片上驱动技术开辟新的前景。在此，我们将单晶硅中的晶圆级纳米孔隙率与孔隙空间内人工肌肉材料的聚合相结合，以合成一种在水性电解质中表现出宏观电致应变的复合材料。就压电驱动而言，电压-应变耦合比性能最佳的陶瓷大三个数量级。我们将这种巨大的电驱动归因于每平方厘米横截面中1000亿个纳米孔的协同作用以及单孔尺度下高达150个大气压的电位依赖性压力。极低的工作电压（0.4至0.9伏）以及可持续且生物相容的基础材料，使得这种复合材料在生物驱动应用方面颇具前景。
