Project description

This project focuses on the investigation of polypyrrole (PPy) in tubular pores in micro-, meso- and macroporous silicon (PSi). PPy offers the possibility to modify the electrical conductivity of PSi in a controlled way. Silicon is given a stringent porous structure, and by functionalising it with an electrically conductive polymer (polypyrrole), the mechanical and functional behaviour is to be controlled and completely new functional properties integrated into silicon. The piezoelectroactuators shown in nanoporous silicon-polypyrrole hybrids offer completely new perspectives for silicon-based electro-mechanical coupling, both with regard to the investigation of fundamental questions, but also with regard to applications of this technologically enormously important semiconductor material.


Based on the findings on "simple" nanoporous silicon functionalised with PPy, the actuory and sensory properties will be investigated and, above all, optimised with regard to a combined fast function and strength. Therefore, hierarchically structured silicon with nanopores on the lowest hierarchical level (h-np Si) is produced. In this process, the walls of macropores (1.1 µm diameter, 215 µm long) are homogeneously nanopore-structured (50-80 nm diameter), so that h-np Si can be produced in the form of a monolithic membrane. A faster ion exchange with macroscopic electrolyte volumes and thus a multiscale pore structure should remove a kinetic transport limitation and also open up new electromechanical properties and structuring options of the hybrid system with polymer.


Project leaders
Prof. Dr. rer. nat. Patrick Huber,

porous silicon


electrochemical actuation

hierarchical materials



1. Brinker, M., Dittrich, G., Richert, C., Lakner, P., Krekeler, T., Keller, T. F., Huber, N. & Huber, P.: Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material. Science advances, 6(40), eaba1483 (2020)

2. Thelen, M., Bochud, N., Brinker, M., Prada, C., & Huber, P.: Laser-Excited Elastic Guided Waves Reveal the Complex Mechanics of Nanoporous Silicon. Nature Communications 12(1), 1-10 (2021)

3. Lakner, P. H., Brinker, M., Seitz, C., Jacobse, L., Vonk, V., Lippmann, M., Volkov, S., Huber, P. & Keller, T. F.: Probing the Electrolyte Transfer in Ultrathin Polypyrrole Films by In Situ X-ray Reflectivity and Electrochemistry. Langmuir, 36(45), 13448-13456 (2020)