Quantifying the Piezoresistive Mechanism in High-Performance Printed Graphene Strain Sensors
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2022Access:
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Eoin Caffrey, James R Garcia, Domhnall O?Suilleabhain, Cian Gabbett, Tian Carey, Jonathan N Coleman, Quantifying the Piezoresistive Mechanism in High-Performance Printed Graphene Strain Sensors, ACS applied materials and interfaces, 2022Download Item:
acsami.1c21623.pdf (Published (author's copy) - Peer Reviewed) 2.196Mb
Abstract:
: Printed strain sensors will be important in applications such as
wearable devices, which monitor breathing and heart function. Such sensors need to
combine high sensitivity and low resistance with other factors such as cyclability, low
hysteresis, and minimal frequency/strain-rate dependence. Although nanocomposite
sensors can display a high gauge factor (G), they often perform poorly in the other
areas. Recently, evidence has been growing that printed, polymer-free networks of
nanoparticles, such as graphene nanosheets, display very good all-round sensing
performance, although the details of the sensing mechanism are poorly understood.
Here, we perform a detailed characterization of the thickness dependence of
piezoresistive sensors based on printed networks of graphene nanosheets. We find
both conductivity and gauge factor to display percolative behavior at low network thickness but bulk-like behavior for networks
above ∼100 nm thick. We use percolation theory to derive an equation for gauge factor as a function of network thickness, which
well-describes the observed thickness dependence, including the divergence in gauge factor as the percolation threshold is
approached. Our analysis shows that the dominant contributor to the sensor performance is not the effect of strain on internanosheet
junctions but the strain-induced modification of the network structure. Finally, we find these networks display excellent cyclability,
hysteresis, and frequency/strain-rate dependence as well as gauge factors as high as 350.
Sponsor
Grant Number
Marie Curie
101030735
Author's Homepage:
http://people.tcd.ie/colemajhttp://people.tcd.ie/careyti
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Author: Coleman, Jonathan; Carey, Tian
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ACS applied materials and interfacesAvailability:
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Nanoscience & MaterialsLicences: