Self-Powered Trace Memorization by Conjunction of Contact-Electrification and Ferroelectricity

Triboelectric nanogenerator (TENG) is a newly invented technology that can effectively harvest ambient mechanical energy from various motions with promising applications in portable electronics, self-powered sensor networks, etc. Here, by coupling TENG and a thin film of ferroelectric polymer, a new application is designed for TENG as a self-powered memory system for recording a mechanical displacement/trace. The output voltage produced by the TENG during motion can polarize the dipole moments in the ferroelectric thin film. Later, by applying a displacement current measurement to detect the polarization density in the ferroelectric film, the motion information of the TENG can be directly read. The sliding TENG and the single-electrode TENG matrix are both utilized for realizing the memorization of the motion trace in one-dimensional and two-dimensional space, respectively. Currently, the ferroelectric thin film with a size of 3.1 mm(2) can record a minimum area changing of 30 mm(2) and such resolution can still be possibly improved. These results prove that the ferroelectric polymer is an effective memory material to work together with TENG and thereby the fabricated memory system can potentially be used as a self-powered displacement monitor.