Abstract
Porous piezoresistive sensors offer promising flexible sensing functionality, such as human joint motion detection and gesture identification. Herein, a facile fabrication method is developed using a microwave-based rapid porogen removal technique for the manufacturing of porous nanocomposite sponges consisting of polydimethylsiloxane (PDMS) and well-dispersed carbon nanotubes (CNTs). The porogen amounts and CNT loadings are varied to tailor the porosity and electrical properties of the porous sensors. The sponges are characterized by a scanning electron microscope (SEM) to compare their microstructures, validate the high-quality CNT dispersion, and confirm the successful nanofiller embedding within the elastomeric matrix. Sponges with a 3 wt% CNT loading demonstrate the highest piezoresistive sensitivity. Experimental characterization shows that the sponges with low porosity have long durability and minimal strain rate dependence. Additionally, the developed sponges with 3 wt% CNTs are employed for the human motion detection using piezoresistive method. One experiment includes fingertip compression measurements on a prosthetic hand. Moreover, the sensors are attached to the chest, elbow, and knee of a user to detect breathing, running, walking, joint bending, and throwing motions.
Highlights
Many fabrication methods have been developed recently for a wide variety of flexible sensors in several applications including human motion detection [1], sensor arrays [2], soft robotics [3], biomechanics [4], structural health monitoring [5], and prosthetic devices [6].These sensors often consist of an elastic polymer that provides the flexible backbone of the sensor while metallic or carbonaceous nanoparticles provide electrical conductivity to the nanocomposites
The fabrication method developed in this study allows the manufacturer to significantly vary the porosity and compressive modulus of the sensors by varying the sugar porogen amount between 70 wt%–85 wt%
Piezoresistive sponges with tailorable electrical and mechanical properties were manufactured with a fabrication process that utilized a novel microwave-assisted rapid porogen removal method that significantly reduced the manufacturing time
Summary
Many fabrication methods have been developed recently for a wide variety of flexible sensors in several applications including human motion detection [1], sensor arrays [2], soft robotics [3], biomechanics [4], structural health monitoring [5], and prosthetic devices [6] These sensors often consist of an elastic polymer that provides the flexible backbone of the sensor while metallic or carbonaceous nanoparticles provide electrical conductivity to the nanocomposites. Common nanoparticles used to improve conductivity in flexible sensors include gold and silver nanowires [7], graphene [8], carbon black [9], and carbon nanotubes (CNTs) [10,11] These highly flexible nanocomposites have been used to produce a signal in response to mechanical input inducing a change in the measurable electrical properties of the material. Additional mechanisms have been developed and employed to improve the sensitivity of flexible piezoresistive sensors by implementing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
