Flexible strain sensor based on biomass‐derived material

Abstract

In recent years, the strain sensors, which can be fixed on human skin to monitor movement, have attracted a considerable attention. In this study, the walnut shell powder was carbonized and mixed with polydimethylsiloxane, followed by encapsulation to prepare a highly flexible strain sensor. The obtained sensor was tested for the electrical and sensing properties. The experimental results revealed that the sensor is stable and reliable in the range of 0% to 40% strain response, while the effective working frequency of the sensor is in the range of 0.01 to 0.5 Hz. Moreover, the carbonized the walnut shell powder/PDMS prepolymer and its curing agent (PDMSCA) strain sensor exhibited an excellent fatigue resistance. No significant attenuation phenomenon was observed after 1000 cycles of stretching. The strain sensor was then attached to a volunteer throat, knee, elbow, and fingers joints. The corresponding human movements determined obvious sensing response and repeatability. This work proposes a new flexible strain sensor based on environmentally friendly materials, which is obtained by means of a facile preparation method. Hence, this work can open up new avenues for the development of novel and effective strain sensors using cost‐effective carbonized materials as filling materials.

A comprehensive review on plant‐based natural fiber reinforced polymer composites: Fabrication, properties, and applications

“…[ 337 ] Strain sensor made of a conductive and flexible carbonized walnut shell powder/polydimethylsiloxane (PDMS) composite exhibited a high performance in detection of human body movements and can be further developed as wearable flexible sensors. [ 338 ] Commercial applications: Enkev Company uses coir and natural latex rubber to manufacture packing boxes and trays. GreenCore Company makes home and office furniture, garden products, consoles, toys, and sporting goods.…”

Flexible and Sensitivity-Adjustable Pressure Sensors Based on Carbonized Bacterial Nanocellulose/Wood-Derived Cellulose Nanofibril Composite Aerogels

“…Natural biomaterialssuch as cellulose fibers and the various types of nanocelluloses including cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BC)have been widely used in the preparation of low-cost and environment-friendly green strain/pressure sensors. , By a facile thermal treatment, the obtained carbonized materials derived from biomass, such as cellulose paper, , cotton fabric, , silk, − and wood, were endowed with excellent electrical conductivity; they were successfully employed to fabricate pressure sensors as active layers. However, the micro/nanostructures of these natural biomaterials were always not adjustable.…”

Conductive, sensing stable and mechanical robust silicone rubber composites for large‐strain sensors

“…To our knowledge, basic human joint motion always reaches the strain of 50%. [11,30] Strain effects on the sensing response are further discussed. The 10-cyclic repeatability of 4R/R at the strain of 30% and 100% is plotted in Figure 5E,F.…”

“…The usage of hybrid carbon nanofillers is aimed at optimizing the conductivities and strain sensing response of rubber composites. [ 30 ] Then their conductivities were compared, combining with the dispersion observations of CNTs. Mechanical strength, elasticity, and strain sensing properties were carefully discussed.…”