Flexible and Stretchable Physical Sensor Integrated Platforms for Wearable Human‐Activity Monitoringand Personal Healthcare

Abstract

Flexible and stretchable physical sensors that can measure and quantify electrical signals generated by human activities are attracting a great deal of attention as they have unique characteristics, such as ultrathinness, low modulus, light weight, high flexibility, and stretchability. These flexible and stretchable physical sensors conformally attached on the surface of organs or skin can provide a new opportunity for human-activity monitoring and personal healthcare. Consequently, in recent years there has been considerable research effort devoted to the development of flexible and stretchable physical sensors to fulfill the requirements of future technology, and much progress has been achieved. Here, the most recent developments of flexible and stretchable physical sensors are described, including temperature, pressure, and strain sensors, and flexible and stretchable sensor-integrated platforms. The latest successful examples of flexible and stretchable physical sensors for the detection of temperature, pressure, and strain, as well as their novel structures, technological innovations, and challenges, are reviewed first. In the next section, recent progress regarding sensor-integrated wearable platforms is overviewed in detail. Some of the latest achievements regarding self-powered sensor-integrated wearable platform technologies are also reviewed. Further research direction and challenges are also proposed to develop a fully sensor-integrated wearable platform for monitoring human activity and personal healthcare in the near future.

Ultrastretchable Fiber Sensor with High Sensitivity in Whole Workable Range for Wearable Electronics and Implantable Medicine

“…However, the Δ R / R 0 of a NTTF 5 @fiber sensor with ε pre = 1600% changed to be as large as 390 for ε = 1135%, and the GF was 21.3 for a strain range from 0% to 150% and 34.22 for a strain range from 200% to 1135%. The sensitivities over the whole strain range were better compared to those of previously reported highly stretchable strain sensors 28, 29, 30, 31, 32…”

Side-chain effect of organic semiconductors in OFET-based chemical sensors

“…Another compelling application of OFET is chemical and biological sensing [7][8][9][10][11][12]. Sensors based on OFETs can be low-weight, low-cost, flexible, and miniaturized [13][14][15][16][17][18]. Analyte molecules can have various effects on organic semiconductors (OSCs), such as doping or quenching induced charge carrier density variation and dipole-induced trapping and retarding of charges [19][20][21][22].…”

A skin-like stretchable colorimetric temperature sensor

“…Ongoing efforts have been devoted to the development of smart and wearable/implantable devices for ubiquitous computing or personalized medical care [1][2][3][4][5]. A key technical issue in designing such wearable devices is to achieve reasonable stretchability and delightful deformability.…”