Abstract
We investigated the relationship between the polarization characteristics of ferroelectric Hf0.5Zr0.5O2 thin-films and data processing capability in physical reservoir computing. Ferroelectric-gate field-effect transistors (FeFETs) with a metal-ferroelectric-metal-insulator-semiconductor structure were employed with varying area ratios between the ferroelectric capacitors and floating gate-electrodes. The voltage applied to the ferroelectric layers was theoretically calculated using load line analysis and determined experimentally. In a time-series prediction task, the FeFETs showed low error rates under conditions that produced multiple hysteresis loops in dynamic transfer waveforms. The results indicate that data processing capability is improved when a substantial portion of polarization is switched.
12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference 1387-1389 2008年1月1日
S. Yoshii, K. Yamaguchi, T. Fujita, K. Kanda, K. Maenaka
16TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2016) 2016年 IOP PUBLISHING LTD
This paper proposes collision-free structure using NdFeB thin-film magnet for vibration energy harvesters. By using stripe shaped NdFeB magnet array on the Si MEMS structure, we finally obtained 3 mN of magnetic repulsive force on 8 x 8 mm(2) specimen with 40 mu m air-gap.
N. Miwatani, T. Fujita, Y. Kitagawa, K. Kanda, K. Maenaka
16TH INTERNATIONAL CONFERENCE ON MICRO AND NANOTECHNOLOGY FOR POWER GENERATION AND ENERGY CONVERSION APPLICATIONS (POWERMEMS 2016) 2016年 IOP PUBLISHING LTD
This paper reports an improvement of structure design of bipolar charged electret energy harvester to prevent an electrical discharge during a corona charging process on electret. We confirmed that differential output power of 33 mu W is obtained with 8.8 g at 350 Hz sinusoidal vibration from the developed device. By using a commercially available power management IC, regulated voltage of 1.8 V is properly obtained and can drive a load resistance more than 500 k Omega.
2016 International Conference on Electronics Packaging (ICEP) 2016年 IEEE
We report a novel stretchable wiring that has self-healing property. The wiring was fabricated by filling conductive magnetic powder into a hollow tube of silicone material. This stretchable wiring has good performance, which is conductivity of 1715 S/cm under nonstretch status and stretchability of 150% with conductivity. In addition, this wiring has good credibility, i.e. enduring 1000 cycles tensile test under strain of 100%. Furthermore, to confirm self-healing property, we applied excessive strain of 250% intentionally. The experiment result shows a fine self-healing property, that the wiring retrieved conductivity at any time by releasing wiring.
2016 IEEE 29TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) 2016年 IEEE
Multimorph structure of Pb(Zr,Ti)O-3 (PZT) thin films by using sputtering deposition, which is compatible with batch-fabrication, was realized for the applications of low voltage driving and large generative force actuators. Test microcantilevers with four layers of PZT thin film were fabricated by dry etching of PZT with metal thin films on a four inch wafer, without deterioration of piezoelectric performance. All PZT layers worked well as piezoelectric material and an actuation test revealed a four-fold displacement per voltage compared with single layer actuations. In addition, a limit of the number of laminated layer for PZT multimorph was also evaluated from point of the view of total stress index.