Ultrasensitive strain gauge with tunable temperature coefficient of resistivity
strain gauge, flexible gauge, Au nanoparticle, sound-wave detection, radial-artery detection, electron tunneling
ABSTRACT We demonstrate an ultrasensitive strain gauge based on a discontinuous metal film with a record detection limit as low as 8.3 × 10–6. Constructed by well-tunable crevices on the nanometer scale within the film, this gauge exhibits an ultrafast dynamic response to vibrations with a frequency range of 1 Hz to 10 kHz. More importantly, the temperature coefficient of resistivity (TCR) of the metal film is tunable owing to the cancellation effect caused by the possibility of tunneling across the nanoscale crevices (showing a negative temperature dependence) and the electron conduction within the metal islands (showing a positive temperature dependence). Consequently, a nullified TCR is achievable when the crevice size can be precisely controlled. Thus, a fabrication strategy to precisely control the nanoscale crevices was developed in this study through the real-time tracking of the electrical conductivity during thermal evaporation. The ultrasensitive strain gauge with a tunable thermal drift introduces numerous opportunities for precision devices and wearable electronics with superior reliability.
Tsinghua University Press
Lizhi Yi,Weihong Jiao,Changming Zhu,Ke Wu,Chao Zhang,Lihua Qian,Shuai Wang,Yingtao Jiang,Songliu Yuan, Ultrasensitive strain gauge with tunable temperature coefficient of resistivity. NanoRes.2016, 9(5): 1346–1357