Multidimensional Force Sensors Based on Triboelectric Nanogenerators for Electronic Skin

Abstract

The ability to detect multidimensional forces is highly desired for electronic skin (E-skin) sensors. Here, based on single-electrode-mode triboelectric nanogenerators (S-TENGs), fully elastic E-skin that can simultaneously sense normal pressure and shear force has been proposed. With the hemispherical curve-structure design and further structural optimization, the pressure sensor exhibits a high linearity and sensitivity of 144.8 mV/kPa in the low-pressure region. By partitioning the lower tribolayer into two symmetric parts, a multidimensional force sensor has been fabricated in which the output voltage sum and ratio of the two S-TENGs can be used for normal pressure and shear force sensing, respectively. When the multidimensional force sensors are mounted at a two-fingered robotic manipulator, the change of the grabbing state can be recognized, indicating that the sensor may have great application potential in tactile sensing for robotic manipulation, human–robot interactions, environmental awareness, and object recognition.

Wearable Triboelectric Nanogenerators Based on Polyamide Composites Doped with 2D Graphitic Carbon Nitride

“…Another approach is to improve the friction composites’ permittivity through doping certain materials into pristine triboelectric layers [ 2 ], such as carbon nanotubes, liquid metals, graphene oxide, metal nanowire/nanoparticle, and BaTiO 3 . Single-layer materials [ 3 ] or two-dimensional (2D) nanomaterials are generally categorized into either 2D allotropes or compounds with crystalline solids consisting of a single layer of atoms. It is of note that various 2D structures [ 4 ] have been discovered, such as graphene, MXene, MoS 2 , WS 2 , and graphitic carbon nitride (g-C 3 N 4 ).…”

Self-Powered Force Sensors for Multidimensional Tactile Sensing

“…Flexible force sensors are becoming increasingly important for tactile and biological mechanical force sensing in a large variety of applications, including health care, robotics, and human–machine interactions. − For instance, wearable and implantable force sensors detect the pulse rhythm and blood pressure to reflect the potential cardiovascular disease. − Also, for robotics, force sensors will enable the function of object perception, which is also a promising device to realize human–machine interactions. − Up to now, there have been many reports focusing on designing the microstructure and improving the sensing materials to increase the sensitivity of force sensors. − Most of the sensors respond to unidirectional force; however, the ability to detect and distinguish normal and shear forces in real time is crucial to provide important information in practice. These parameters cannot be directly obtained with the traditional force sensors, while future force sensors are required to perform integrated sensing capabilities for manipulation tasks like realizing automation of experimental operations with robotic hands. − Hence, to achieve higher manipulative and intelligent levels of force sensing applications, an integrated force sensor that could sense the value and directions of force simultaneously is an inspiring and challenging research topic. − …”

Environmentally Tolerant Ionic Hydrogel with High Power Density for Low-Grade Heat Harvesting

“…Flexible electronics have attracted more and more attention due to their excellent flexibility, portability, biocompatibility, and broad application prospects − in the area of health monitoring, − electronic skin, − artificial intelligence, and so on, which have a profound impact on people’s lives. As frequent charging is inconvenient for applications such as health monitoring, it is urgent to develop a facile and efficient energy-harvesting method for flexible equipment.…”