Printable Elastic Conductors by in situ Formation of Silver Nanoparticles from Silver Flakes：Dr. Naoji Matsuhisa and Professor Takao Someya, Department of Electrical Engineering and Information Systems, and other researchers.

Authors

Naoji Matsuhisa, Daishi Inoue, Peter Zalar, Hanbit Jin, Yorishige Matsuba, Akira Itoh, Tomoyuki Yokota, Daisuke Hashizume & Takao Someya

Abstract

Printable elastic conductors promise large-area stretchable sensor/actuator networks for healthcare, wearables and robotics. Elastomers with metal nanoparticles are one of the best approaches to achieve high performance, but large-area utilization is limited by difficulties in their processability. Here we report a printable elastic conductor containing Ag nanoparticles that are formed in situ, solely by mixing micrometre-sized Ag flakes, fluorine rubbers, and surfactant. Our printable elastic composites exhibit conductivity higher than 4,000 S cm⁻¹ (highest value: 6,168 S cm⁻¹) at 0% strain, and 935 S cm⁻¹ when stretched up to 400%. Ag nanoparticle formation is influenced by the surfactant, heating processes, and elastomer molecular weight, resulting in a drastic improvement of conductivity. Fully printed sensor networks for stretchable robots are demonstrated, sensing pressure and temperature accurately, even when stretched over 250%.

Nature Materials: https://www.nature.com/articles/nmat4904

EurekAlert : https://www.eurekalert.org/pub_releases/2017-05/uot-stl051117.php

ScienceDaily : https://www.sciencedaily.com/releases/2017/05/170515111621.htm