MEGUMI AKAI-KASAYA
MY LATEST RESEARCH
We demonstrate that the addition of a molecule with high redox activity to a carbon nanotube (CNT) field-effect transistor provides tunable current fluctuation noise. A unique charge-trap state in the vicinity of the CNT surface due to the presence of the single molecule is the origin of the noise, which generates a prominent and unique slow discrete random telegraph signal in the device current. The controllability of the noise may contribute to the expansion of noise utilization in future bio-inspired devices.
Stochastic resonance (SR) is a noise-enhanced signal transmission and detection system. We demonstrated SR in a summing network based on a single-walled carbon nanotube (SWNT) device that detects small subthreshold signals with very low current flow. The functional capabilities of the present small-size summing network SR device, which rely on dense nanomaterials and exploit intrinsic spontaneous noise at room temperature, offer a glimpse of future bio-inspired electronic devices.
Single walled carbon nanotube-based stochastic resonance device with molecular self-noise source
Applied Physics Letters, in press (2017)
Doctor of Science, Ph.D.
Assistant Professor
Department of Precision Science &Technology
Graduate School of Engineering
Osaka University
Room-temperature discrete-charge-fluctuation dynamics of a single molecule adsorbed on a carbon nanotube
Nanoscale, Vol. 9, pp.10674-10683 (2017).
Stochastic resonance (SR) is a noise-enhanced signal transmission and detection system. We demonstrated SR in a summing network based on a single-walled carbon nanotube (SWNT) device that detects small subthreshold signals with very low current flow. The functional capabilities of the present small-size summing network SR device, which rely on dense nanomaterials and exploit intrinsic spontaneous noise at room temperature, offer a glimpse of future bio-inspired electronic devices.
Single walled carbon nanotube-based stochastic resonance device with molecular self-noise source
Applied Physics Letters, in press (2017)
The current-voltage characteristics of P3HT monolayers could be best fitted using a power law. These results suggest that the nonlinear conductivity can be explained using a Coulomb blockade (CB) mechanism. A model is proposed in which an isotropic extended charge state
exists, as predicted by quantum calculations, and percolative charge transport occurs within an array of
small conductive islands. It suggested that percolative charge transport based on the CB effect is a significant factor giving rise to nonlinear conductivity in organic materials.
Coulomb-blockade transport in two-dimensional conductive polymer monolayer
Physical Review Letters, 115, 196801 (2015)
On the Growing Polymer Neural Networks
We present a prototype of molecular neural networks consisting of conducting polymer PEDOT/PSS [poly (3, 4-ethylenedioxythiophene) doped with poly (styrene sulfonate) anions] wires. The PEDOT wire grow dendritically and connect between the electrodes immersed in its monomer solution. Through real experimentals, we demonstrate that the molecular networks acquire basic logical functions as a result of the supervised learning. A neural-network skeleton having differential inputs and readout electrodes (neurons) in the solution has been used to demonstrate a neural network learning growth of the polymer wires. These results implies that they expand variety of present neuromorphic computing architectures designed mainly for solid-state CMOS devices.