739wileyonlinelibrary.com collection, wind energy gathering, and so on. [3][4][5] Meanwhile, by utilizing the universal availability of tribo-electricity, this energy generation technique was also applied for designing various self-powered sensor devices, such as motion detectors, skin sensor, liquid sensor, and so on. [6][7][8] Generally speaking, the mainstreams of the research for TENG are developing into two paths. One is related to the enhancement of the power generation from TENG. [ 9,10 ] A common characteristic of the TENG is a high output voltage (hundreds of volts) but low output current. It is therefore necessary to increase charge separation cycles within the limited time in order to improve the charge transfer rate through the devices, which is the current. In addition to high effi ciency, another research direction of TENG is to enrich its functionality as self-powered devices. As a result, a series of sensor devices as well as several hybrid power systems based on the concept of tribo-electrifi cation are designed and applied for various purposes. [ 11,12 ] Consequently, in order to further popularize the practical utilization of TENG as a low-cost and sustainable new energy technology, it is quite necessary to keep developing some novel and functional applications for TENG technique.On the other hand, polymer Poly(vinylidene fl uoride-trifluoroethylene) (P(VDF-TrFE)) [13][14][15] is a kind of ferroelectric material that has been widely studied for organic memory devices, where two different orientations of dipole moments (up and down) can be briefl y considered as "0" and "1" signal for computation and information storage. The dipole moment in P(VDF-TrFE) also can modulate the distribution of local electric fi eld in the organic active layer, which makes a great contribution to enhance charge separation and transport in the organic electronics devices. [ 16,17 ] The spontaneous polarization of the P(VDF-TrFE) is very sensitive to the applied electric fi eld and less depending on the conduction current, which is very suitable for the TENG's output characteristic of high voltage and low current. Meanwhile, the dipole switching time of such materials is less than millisecond, which is also compatible for the motion of TENG. Furthermore, it has been found that the ferroelectric performance of P(VDF-TrFE) remains unchanged until for more than 1 × 10 7 times of switching, [ 18 ] which confi rmed the repeatability of the dipole switching and the possibility of using this material for some real applications in the fi eld of memory devices. All these facts inspired us to
Self-Powered Trace Memorization by Conjunction of Contact-Electrifi cation and FerroelectricityXiangyu Chen , Mitsumasa Iwamoto , Zhemin Shi , Limin Zhang , and Zhong Lin Wang * 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 f...
