Could Polymer beads power your pacemaker or smart watches?
An international team of researchers from Riga Technical University (Latvia), the RMIT University (Australia), and the MESA+ Institute (the Netherlands), together with Ignaas Jimidar (Vrije Universiteit Brussel – Department of Chemical Engineering, CHIS), has discovered a simple and environmentally friendly way to power the next generation of self-charging electronics, which is now published in the prestigious Nano Energy journal for energy harvesting nanodevices.
By making tiny plastic spheres move against each other, they generate electricity through friction. Instead of using complex fluoropolymer-based materials, the researchers created ultrathin, structured layers of polymethyl methacrylate (PMMA) spheres using a simple rubbing technique. Typically, producing such ultrathin films requires highly advanced equipment and is both costly and difficult.
The result is thin films only a few micrometers thick—about ten times thinner than a human hair—that can be inexpensively applied to any hard surface. By pressing two layers of spheres together, one made of smaller spheres and the other of slightly larger ones, the particles become electrically charged through the triboelectric effect. This is the same effect that causes a balloon to become charged when rubbed on hair during dry winter days, often resulting in a small static shock.
When the layers were pressed together near a vibration speaker (like in a smartphone), the researchers were able to generate nearly 0.5 kilovolts of voltage, albeit with a very small current of 4 nanoamperes. This opens up the possibility of powering a smartwatch during exercise—leading to more sustainable energy use.
Because the method uses no solvents and does not rely on toxic fluoropolymers, it is both more environmentally friendly and easier to produce. The technique thus offers a fast, scalable way to create energy-harvesting surfaces using nothing more than microscopic plastic spheres.
Source link: Strong piezoelectric-like electromechanical response from single granular PMMA interface - ScienceDirect
