Super-Stretchable Resistive Strain Sensor Based on Ecoflex–Gold Nanocomposites

Abstract

Superstretchable resistive strain sensors can reversibly undergo severe deformations in response to different mechanical stimuli, leading to a variation in their ohmic resistance. They are finding an increasing number of applications in wearable electronics, biomedical devices, and soft robotics. The development of fabrication process of reliable, highly sensitive, and biocompatible superstretchable strain sensors remains a challenge, especially in view of their integration with medical devices. Here, we demonstrate the fabrication of a high-strain resistive sensor based on Ecoflex elastomeric films and conductive Au clusters, obtained by supersonic cluster beam deposition. An extensive characterization of the electromechanical behavior of the sensor shows stable operation up to 4500 working cycles, with a maximum strain of 500% and a gauge factor of 124. Different mechanical stimuli, such as elongation and indentation, can be detected, and the easy coupling of the sensor with an inflatable balloon-type urinary catheter is demonstrated. Aiming at shedding light on the observed electromechanical mechanisms, the nanostructured morphology of the metal–polymer hybrid layer was investigated by low-vacuum scanning electron microscopy.

Flexible Strain Sensor Based on Copper/Graphene Composite Films

“…Consequently, the MGCC sensor is highly suitable for monitoring minute strains in the human body, such as subtle changes in facial muscle movements. Figure d shows a comparison of the sensors with those reported in the literature. − MGCC achieves a wide strain-sensing range and high sensitivity. As shown in Figure e, the strain loading test at 600 mm/min achieved a response/recovery time of 160/360 ms, and the shorter response/recovery time is favorable for the real-time monitoring of human bio signals.…”

Stretchable Substrate Surface-Embedded Inkjet-Printed Strain Sensors for Design Customizable On-Skin Healthcare Electronics

“…It can print with a resolution of tens of micrometers, which would be sufficiently small for skin-mountable sensors . The inkjet printing has fabricated capacitive or resistive strain sensors. ,, Resistive strain sensors are often used because they are simpler to manufacture and can measure larger strains with higher sensitivity …”

High Performance Strain Sensor Based on Carbon Black/Graphene/Ecoflex for Human Health Monitoring and Vibration Signal Detection

“…The material of the flexible base determines the sensing range of the sensor. The main flexible materials used in the existing flexible strain sensors include Ecoflex, polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), and styrene–ethylene–butylene–styrene (SEBS). − Because of the simple preparation process (simple mixing and mixing of glue A and glue B), good tensile properties (tensile factor of about 600%), and good human compatibility, Ecoflex is widely used in the field of flexible strain sensors. For example, Antonio et al prepared a high-tensile strain sensor based on carbon nanotubes and Ecoflex, which had a strain sensing range of up to 300%, but its response time and recovery time were too large (600 and 800 ms, respectively) .…”