Improvement in Strain Sensor Stability by Adapting the Metal Contact Layer

Abstract

Research on stretchable strain sensors is actively conducted due to increasing interest in wearable devices. However, typical studies have focused on improving the elasticity of the electrode. Therefore, methods of directly connecting wire or attaching conductive tape to materials to detect deformation have been used to evaluate the performance of strain sensors. Polyaniline (PANI), a p-type semiconductive polymer, has been widely used for stretchable electrodes. However, conventional procedures have limitations in determining an appropriate metal for ohmic contact with PANI. Materials that are generally used for connection with PANI form an undesirable metal-semiconductor junction and have significant contact resistance. Hence, they degrade sensor performance. This study secured ohmic contact by adapting Au thin film as the metal contact layer (the MCL), with lower contact resistance and a larger work function than PANI. Additionally, we presented a buffer layer using hard polydimethylsiloxane (PDMS) and structured it into a dumbbell shape to protect the metal from deformation. As a result, we enhanced steadiness and repeatability up to 50% strain by comparing the gauge factors and the relative resistance changes. Consequently, adapting structural methods (the MCL and the dumbbell shape) to a device can result in strain sensors with promising stability, as well as high stretchability.

The 0-3 Lead Zirconate-Titanate (PZT)/Polyvinyl-Butyral (PVB) Composite for Tactile Sensing

“…Tactile sensing is an essential tool used in instrumentation electronics for evaluating physical parameters such as stress, strain, pressure, and force [ 1 , 2 , 3 ]. A wide range of technologies, including resistive, capacitive, piezoelectric, triboelectric, optical, and magnetic sensors are available for tactile sensing.…”

Dilute Polymerization of Aniline on PDMS Substrate via Surface Modification Using (3-Aminopropyl)Triethoxysilane for Stretchable Strain Sensor

“…Conductive polymers have the electrical and optical properties of metals as well as mechanical properties of original polymers; hence, extensive research is currently underway on their potential applications [ 1 , 2 , 3 , 4 , 5 ]. Polyaniline (PANI) has good electrical properties and high mechanical strength, thereby rendering it suitable for application to flexible-substrate-based wearable sensors [ 6 , 7 , 8 ].…”