Recently, PhD student Qingshen Jing and Professor Pingchou Han of the College of Engineering, Peking University, published a paper entitled “Self-powered thin-film motion vector sensor” in Nature Communications (DOI: 10.1038/ncomms9031). Jing serves as the first author and his supervisor Han the correspondence author. The abstract of their work reads as follows.

Harnessing random micro-meso scale ambient energy is not only clean and sustainable, but it also enables self-powered sensors and devices to be realized. Here we report a robust and self-powered kinematic vector sensor fabricated using highly-pliable organic films that can be bent to spread over curved and uneven surfaces. The device derives its operational energy from a close-proximity triboelectrification of two surfaces; a polytetrafluoroethylene film coated with a 2-column array of copper electrodes that constitutes the mover and a polyimide film with the top and bottom surfaces coated with a 2-column aligned array of copper electrodes that comprises the stator. During relative reciprocations, the electrodes in the mover generate electric signals of ±5 V to attain a peak power density of ≥ 65 mW m-2 at a speed of 0.3 ms-1. From our 86,000 sliding motion tests of kinematic measurements, the sensor exhibits excellent stability, repeatability and strong signal durability.