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Nearly isotropic piezoresistive response due to charge detour conduction in nanoparticle thin films.

Jiang CW, Ni IC, Tzeng SD, Kuo W - Sci Rep (2015)

Bottom Line: Disordered interparticle tunneling introduces microscopic detour of charge conduction so as to reduce gauge factors.The disorder also results in large resistance change when current flows in the direction perpendicular to a unidirectional strain, reducing response anisotropy.Cracks form in devices under prolonged cyclic bending and slightly reduce gauge factor.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.

ABSTRACT
Piezoresistive responses of nanoparticle thin-film strain sensors on flexible polyimide substrates were studied. Disordered interparticle tunneling introduces microscopic detour of charge conduction so as to reduce gauge factors. The disorder also results in large resistance change when current flows in the direction perpendicular to a unidirectional strain, reducing response anisotropy. For practical usages, stability and endurance of these strain sensors are confirmed with 7 × 10(4) bending cycles. Cracks form in devices under prolonged cyclic bending and slightly reduce gauge factor.

No MeSH data available.


Related in: MedlinePlus

The change of resistance and gauge factor of a MHA sensor while the applied strain cyclically changes between +0.90% and −0.77% with a period of 6 sec.(a) the resistance change near cycle number N ~ 1000 and 60000. (b–c) The change of R0 and gauge factor with N.
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f5: The change of resistance and gauge factor of a MHA sensor while the applied strain cyclically changes between +0.90% and −0.77% with a period of 6 sec.(a) the resistance change near cycle number N ~ 1000 and 60000. (b–c) The change of R0 and gauge factor with N.

Mentions: Besides studying what affects the gauge factor of the AuNP strain sensors, examining their stability and endurance are also important for practical applications. To this aim, we performed fatigue tests, repeatedly bent the sensor (6 s per cycle) to have the strain ε cyclically change from +0.90% to −0.77%. The testing video can be found in Supporting Information. Figure 5a shows the corresponding change of resistance of a MHA device when the cycle number N was about 1000 and 60000. It demonstrates the sensor has good endurance and works well even after bending more than 6 × 104 times. However, R0 had an obvious increase of about 20% in the first 2000 cycles, as shown in Fig. 5b. This may be caused by the generation of some cracks on the AuNP film. The fatigue test introduced some defects and cracks on the Au/Ni electrodes and AuNP films as illustrated in Figure S9. On the electrodes, long and straight cracks could be as wide as 10 s nm. On the contrary, some isolated defects and small cracks, typically 10 nm in width would be found on the MHA-AuNP films. It has been reported that under strain the cracks become pronounced so that an important factor in strain sensor responses is the possible strain-induced formation of cracks26.


Nearly isotropic piezoresistive response due to charge detour conduction in nanoparticle thin films.

Jiang CW, Ni IC, Tzeng SD, Kuo W - Sci Rep (2015)

The change of resistance and gauge factor of a MHA sensor while the applied strain cyclically changes between +0.90% and −0.77% with a period of 6 sec.(a) the resistance change near cycle number N ~ 1000 and 60000. (b–c) The change of R0 and gauge factor with N.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4502517&req=5

f5: The change of resistance and gauge factor of a MHA sensor while the applied strain cyclically changes between +0.90% and −0.77% with a period of 6 sec.(a) the resistance change near cycle number N ~ 1000 and 60000. (b–c) The change of R0 and gauge factor with N.
Mentions: Besides studying what affects the gauge factor of the AuNP strain sensors, examining their stability and endurance are also important for practical applications. To this aim, we performed fatigue tests, repeatedly bent the sensor (6 s per cycle) to have the strain ε cyclically change from +0.90% to −0.77%. The testing video can be found in Supporting Information. Figure 5a shows the corresponding change of resistance of a MHA device when the cycle number N was about 1000 and 60000. It demonstrates the sensor has good endurance and works well even after bending more than 6 × 104 times. However, R0 had an obvious increase of about 20% in the first 2000 cycles, as shown in Fig. 5b. This may be caused by the generation of some cracks on the AuNP film. The fatigue test introduced some defects and cracks on the Au/Ni electrodes and AuNP films as illustrated in Figure S9. On the electrodes, long and straight cracks could be as wide as 10 s nm. On the contrary, some isolated defects and small cracks, typically 10 nm in width would be found on the MHA-AuNP films. It has been reported that under strain the cracks become pronounced so that an important factor in strain sensor responses is the possible strain-induced formation of cracks26.

Bottom Line: Disordered interparticle tunneling introduces microscopic detour of charge conduction so as to reduce gauge factors.The disorder also results in large resistance change when current flows in the direction perpendicular to a unidirectional strain, reducing response anisotropy.Cracks form in devices under prolonged cyclic bending and slightly reduce gauge factor.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, National Chung Hsing University, Taichung 402, Taiwan.

ABSTRACT
Piezoresistive responses of nanoparticle thin-film strain sensors on flexible polyimide substrates were studied. Disordered interparticle tunneling introduces microscopic detour of charge conduction so as to reduce gauge factors. The disorder also results in large resistance change when current flows in the direction perpendicular to a unidirectional strain, reducing response anisotropy. For practical usages, stability and endurance of these strain sensors are confirmed with 7 × 10(4) bending cycles. Cracks form in devices under prolonged cyclic bending and slightly reduce gauge factor.

No MeSH data available.


Related in: MedlinePlus