Water as an energy carrier: nanoporous silicon generates electricity from friction with water
- Oct 22, 2025
- 2 min read
A European research team involving scientists from DESY and Hamburg University of Technology (TUHH) has developed a novel way for converting mechanical energy into electricity – by using water confined in nanometre-sized pores of silicon as the active working fluid.
In a study published in Nano Energy (Elsevier), the scientists demonstrate that the cyclic intrusion and extrusion of water in water-repellentnanoporous silicon monoliths can produce measurable electrical power.
Electricity generated by friction in tiny pores
The developed system, known as an Intrusion–Extrusion Triboelectric Nanogenerator (IE-TENG), uses pressure to repeatedly force water into and out of nanoscale pores. During this process, charge generation occurs at the interface between the solid and the liquid.
This is a type of friction electricity that often occurs in everyday life. An example that everyone is familiar with: walking across a PVC carpet with shoes on. Electrons transfer from one body to another, accumulating a charge that is suddenly discharged when a third body is touched. For example, when touching a door handle, the charge flows away and you get a small electric shock.
The achieved energy conversion efficiency of up to 9% ranks among the highest ever reported for solid–liquid nanogenerators. “Even pure water, when confined at the nanoscale, can enable energy conversion,” says Patrick Huber, spokesperson of the BlueMat – Water-Driven Materials Excellence Cluster at the Hamburg University of Technology (TUHH) and DESY.
Luis Bartolomé (CIC energiGUNE) adds: “Combining nanoporous silicon with water enables an efficient, reproducible power source — without exotic materials, but just by using the most abundant semiconductor on earth, silicon, and the most abundant liquid, water.”
Materials design as the key
“A crucial step was the development of precisely engineered silicon structures that are simultaneously conductive, nanoporous, and hydrophobic,” explains Manuel Brinker from the Hamburg University of Technology. “This architecture allows us to control the motion of water inside the pores — making the energy conversion process both stable and scalable.”
The technology paves the way for autonomous, maintenance-free sensor systems — for example in water detection, sports and health monitoring in smart garments, or haptic robotics, where touch or motion directly generates an electrical signal. “Water-driven materials mark the beginning of a new generation of self-sustaining technologies,” emphasize the corresponding authors Simone Meloni (University of Ferrara) and Yaroslav Grosu (CIC energiGUNE).
Reference Triboelectrification during non-wetting liquids intrusion–extrusion in hydrophobic nanoporous silicon monoliths
Luis Bartolomé, Nicola Verziaggi, Manuel Brinker, Eder Amayuelas, Sebastiano Merchori, Mesude Z. Arkan, Raivis Eglītis, Andris Šutka, Mirosław Chorążewski, Patrick Huber, Simone Meloni, Yaroslav Grosu
