writer：Mufang Li, Haiying Li, Weibing Zhong, Qinghua Zhao, and Dong Wang*
keywords：stretchable conductive PPy/PU elastomer, netlike microcrack structure, stretching strain sensor, human breath detection, porous PU substrate, reversible change in electrical resistance
source：期刊
Issue time：2013年
The development of wearable electronics that can monitor
human physiological information demands specially structured materials with
excellent stretchability and electrical conductivity. In this study, a new
stretchable conductive polypyrrole/polyurethane (PPy/PU) elastomer was
designed and prepared by surface diffusion and in situ polymerization of PPy
inside and on porous PU substrates. The structures allowed the formation of
netlike microcracks under stretching. The netlike microcrack structures make
possible the reversible changes in the electrical resistance of PPy/PU
elastomers under stretching and releasing cycles. The variations in
morphology and chemical structures, stretchability, and conductivity as
well as the sensitivity of resistance change under stretching cycles were
investigated. The mechanism of reversible conductivity of the PPy/PU
elastomer was proposed. This property was then used to construct a
waistband-like human breath detector. The results demonstrated its potential
as a strain sensor for human health care applications by showing reversible resistance changes in the repeated stretching and
contracting motion when human breathes in and out.