A durable nanomesh on-skin strain gauge for natural skin motion monitoring with minimum mechanical constraints

Abstract

Ultraconformable strain gauge can be applied directly to human skin for continuous motion activity monitoring, which has seen widespread application in interactive robotics, human motion detection, personal health monitoring, and therapeutics. However, the development of an on-skin strain gauge that can detect human body motions over a long period of time without disturbing the natural skin movements remains a challenge. Here, we present an ultrathin and durable nanomesh strain gauge for continuous motion activity monitoring that minimizes mechanical constraints on natural skin motions. The device is made from reinforced polyurethane-polydimethylsiloxane (PU-PDMS) nanomeshes and exhibits excellent sustainability, linearity, and durability with low hysteresis. Its thinness geometry and softness provide minimum mechanical interference on natural skin deformations. During speech, the nanomesh-attached face exhibits skin strain mapping comparable to that of a face without nanomeshes. We demonstrate long-term facial stain mapping during speech and the capability for real-time stable full-range body movement detection.

Three-Dimensional Arterial Pulse Signal Acquisition in Time Domain Using Flexible Pressure-Sensor Dense Arrays

“…Many sensor types have been tested for pulse-taking at the radial artery, including optical [ 9 ], polyvinylidene fluoride (PVDF) [ 10 , 11 ], ultrasonic Doppler [ 12 , 13 ], piezoelectric [ 14 , 15 , 16 ], strain gauges [ 17 ], and pressure sensors [ 18 ]. Recently, many researchers have examined on binocular vision theory [ 19 ], CCD sensors [ 20 ], CMOS image sensors [ 21 ], 3D digital image correlation methods [ 22 ], optical fiber sensors [ 23 , 24 ], millimeter wave devices [ 25 ], and RF sensors [ 26 ], among other approaches.…”

“…With the development of flexible materials, some flexible sensors and sensor arrays have been fabricated for arterial pulse acquisition [ 17 , 27 , 28 , 29 , 30 , 31 ]. The flexible sensors are thin, soft and stretchable, and show great potential in future wearable devices.…”

Fused Filament Fabrication of Polymers and Continuous Fiber-Reinforced Polymer Composites: Advances in Structure Optimization and Health Monitoring

“…These flexible strain sensors open the way to numerous applications as sensing soft structures (interactive robotics, human motion detection, personal health monitoring, etc.) [ 82 ]. More detail about all the possibilities of 3D printing to create sensors can be found in these two reviews [ 13 , 83 ].…”

“…More importantly, the recorded signal from strain gauge printed onto a polymeric base suffers from non-linearity, hysteresis, and repeatability deviation, implying drastic corrections of the signal to accurately assess strain [ 76 , 98 ]. Current developments of strain-gauge technology involve the miniaturization of the sensor facilitating 2D strain-field assessment [ 82 ] and improvement of the sensor device design to reduce the viscoelastic effects on the signal, and hence, reduce the correction severity.…”

Hydrogel Cryo‐Microtomy Continuously Making Soft Electronic Devices

“…Moreover, soft electronic devices are expected to be thin enough to render the device‐tissue interface as seamless as possible to reduce disturbance. [ 6,7 ] It is common to deposit high‐modulus materials on low‐modulus substrate or decorate electronic devices with low‐modulus cladding to endow conventional electronic devices with softness. [ 8–12 ] However, it is challenging to make soft electronic devices with both high controllability and yield at one step needed for practical applications, because low‐modulus components easily deform with varying microstructures during processing although high‐modulus components do not, resulting in unstable interfaces between them during fabrication.…”