Comparison of Piezoresistive Monofilament Polymer Sensors

Abstract

The development of flexible polymer monofilament fiber strain sensors have many applications in both wearable computing (clothing, gloves, etc.) and robotics design (large deformation control). For example, a high-stretch monofilament sensor could be integrated into robotic arm design, easily stretching over joints or along curved surfaces. As a monofilament, the sensor can be woven into or integrated with textiles for position or physiological monitoring, computer interface control, etc. Commercially available conductive polymer monofilament sensors were tested alongside monofilaments produced from carbon black (CB) mixed with a thermo-plastic elastomer (TPE) and extruded in different diameters. It was found that signal strength, drift, and precision characteristics were better with a 0.3 mm diameter CB/TPE monofilament than thick (∼2 mm diameter) based on the same material or commercial monofilaments based on natural rubber or silicone elastomer (SE) matrices.

Effect of the Elastomer Matrix on Thermoplastic Elastomer-Based Strain Sensor Fiber Composites

“…The electrical relaxation was similar to the system with non-vulcanized natural rubber. Melnykowycz et al investigated different elastomer sensor materials using combined quasi-static and dynamic tensile tests [17]. No correlation between mechanical and electrical relaxation was observed in this study.…”

“…In this attempt, a piezoresistive thermoplastic elastomer-based strain gauge fiber was developed [6]. This fiber sensor, with a diameter of 0.3 mm, was based on the thermoplastic elastomer styrene-ethylene/butylene-styrene triblock copolymer (TPS) filled with a high loading of non-spherical carbon black to achieve a relatively linear resistance change over a strain range up to 200% [17]. This approach has several advantages such as low material cost (TPS and carbon black), simple manufacturing, applicability to a wide range of geometries (if adhered to sample and embedded in a matrix) and low stiffness [18,19].…”

Fabrication and characterization of vapor grown carbon nanofiber reinforced flexible polymer composites

“…Although, SEBS can be filled with various nanofillers [26][27][28][29], depending on our experience and previous studies CNFs are one of the most suitable materials [16,18]. Their contribution to mechanical property improvement stemmed from their unique structure.…”

Force Sensing Resistor and Evaluation of Technology for Wearable Body Pressure Sensing

“…When a sensor is built to exploit percolation (but similar procedure is used for quantum tunneling based sensors) the resistance of a composite material is measured through the use of some electrodes that are in contact with the polymeric composite. Those electrodes can be embedded inside the material during fabrication [34,35], glued to material [36,37], or in contact with it [37][38][39]. In the first two cases surface resistance between electrodes and composite is constant; otherwise if the electrodes are not glued, surface resistance variation can have big impact on the overall effect [31,37].…”