Login / Signup

Printable G-Putty for Frequency- and Rate-Independent, High-Performance Strain Sensors.

Daniel P O'DriscollSean McMahonJames GarciaSonia BiccaiCian GabbettAdam G KellySebastian BarwichMatthias MoebiusConor S BolandJonathan N Coleman
Published in: Small (Weinheim an der Bergstrasse, Germany) (2021)
While nanocomposite electromechanical sensors are expected to display reasonable conductivity and high sensitivity, little consideration is given to eliminating hysteresis and strain rate/frequency dependence from their response. For example, while G-putty, a composite of graphene and polysiloxane, has very high electromechanical sensitivity, its extreme viscoelasticity renders it completely unsuitable for real sensors due to hysteretic and rate-/frequency-dependent effects. Here it is shown that G-putty can be converted to an ink and printed into patterned thin films on elastic substrates. A partial graphene-polymer phase segregation during printing increases the thin-film conductivity by ×106 compared to bulk, while the mechanical effects of the substrate largely suppress hysteresis and completely remove strain rate and frequency dependence. This allows the fabrication of practical, high-gauge-factor, wearable sensors for pulse measurements as well as patterned sensors for low-signal vibration sensing.
Keyphrases
  • low cost
  • blood pressure
  • carbon nanotubes
  • high frequency
  • room temperature
  • climate change
  • heart rate
  • high resolution
  • mass spectrometry
  • walled carbon nanotubes