Development of a Waterproof Crack-Based Stretchable Strain Sensor Based on PDMS Shielding

Abstract

This paper details the design of a poly(dimethylsiloxane) (PDMS)-shielded waterproof crack-based stretchable strain sensor, in which the electrical characteristics and sensing performance are not influenced by changes in humidity. This results in a higher number of potential applications for the sensor. A previously developed omni-purpose stretchable strain (OPSS) sensor was used as the basis for this work, which utilizes a metal cracking structure and provides a wide sensing range and high sensitivity. Changes in the conductivity of the OPSS sensor, based on humidity conditions, were investigated along with the potential possibility of using the design as a humidity sensor. However, to prevent conductivity variation, which can decrease the reliability and sensing ability of the OPSS sensor, PDMS was utilized as a shielding layer over the OPSS sensor. The PDMS-shielded OPSS sensor showed approximately the same electrical characteristics as previous designs, including in a high humidity environment, while maintaining its strain sensing capabilities. The developed sensor shows promise for use under high humidity conditions and in underwater applications. Therefore, considering its unique features and reliable sensing performance, the developed PDMS-shielded waterproof OPSS sensor has potential utility in a wide range of applications, such as motion monitoring, medical robotics and wearable healthcare devices.

Highly durable crack sensor integrated with silicone rubber cantilever for measuring cardiac contractility

“…Crack sensors exposed to culture media behave very unstably like variable resistors. Furthermore, as for the previous PDMS-coating method proposed by S. K. Hong et al, the protection layer is physically combined with the crack sensor via spin-coating, which also affects the long-term durability of the crack sensor [16]. However, the proposed crack sensor was chemically bonded to a very thin PDMS film via plasma bonding and can be used very reliably in various ionic liquids.…”

“…Typical highsensitivity sensors in the field of microelectromechanical system (MEMS) include silicon nanowires (SiNWs), graphene or carbon nanotube (CNT) composites, crack sensors, etc. [10][11][12][13][14][15][16][17][18][19][20][21]. Koumela et al…”

One-Step Laser Encapsulation of Nano-Cracking Strain Sensors

“…We have previously fabricated nano-crack sensors for wearable devices with a higher GF and a wider strain range as compared to those possessed by the existing stretchable strain sensors. [ 27 , 29 ]. The prepared PU solution was used to make a PU membrane by spin coating it onto a glass slide, controlling the thickness of the membrane via the spinning speed (thickness of ~100 μm at 250 rpm).…”

Wearable Electromechanical Sensors and Its Applications

“…In addition, lower modulus materials are popular for wearable electromechanical sensor, which can further decrease the response speed of resistive sensors. Moreover, based on structural design, the newly developed crack-based piezoresistive sensors show an appealing response time (about 20 ms) because cracks can reversibly connect and disconnect with loading and unloading of mechanical stimuli [15].…”