Flexible strain sensor with high performance based on PANI/PDMS films
Abstract A high strain sensor composed of elastomer polydimethylsiloxane (PDMS) and polyaniline (PANI) was fabricated by electrodeposition method for PANI preparation and daubing method for PDMS preparation. This kind of sensor could subject to a large tensile strain (∼50%) and revealed a high gauge factor (54 at 50% strain), which was higher than other sensors reported previously. Also, the sensor displayed a current with a magnitude of mA when applied to 1 V, indicating it didn't need expensive and huge test equipment. Moreover, cyclic strain on the sensor obtained repeatable resistive responses. Its work mechanisms were discussed. The flexible sensor was proved to be useful in sensing strains and other various applications.
This paper presents an evaluation of the piezocone penetration test (PCPT) interpretation methods and the development of new correlation methods for reasonably estimating the consolidation parameters of cohesive soils, namely, the constrained modulus and overconsolidation ratio (OCR). Laboratory and in situ PCPT test data collected from seven sites in Louisiana were used in this study. Shelby tube samples were collected and used to evaluate the consolidation properties in a laboratory. Statistical analyses were conducted to evaluate the current interpretation methods and to explore new correlations. The results of this study showed that the PCPT data can be reasonably implemented to calculate the constrained modulus and OCR of cohesive soils. Backcalculated constrained modulus and OCR parameters from field measurements are in close agreement with PCPT-derived values.