Self-powered Tactile Sensor Research Articles

Binary cooperative flexible magnetoelectric materials working as self-powered tactile sensors

This study will demonstrate the fabrication of binary cooperative flexible magnetoelectric materials and their application in self-powered tactile sensors.

A Deformable Foam-Layered Triboelectric Tactile Sensor with Adjustable Dynamic Range

The triboelectric effect utilizes the electric potential of materials to generate an electrical output through electrostatic induction between the two oppositely charged surfaces, which grants them unique self-powered characteristics. By utilizing this effect, self-powered tactile sensors have been studied in the previous researches. However, the conventional triboelectric tactile sensors have drawbacks of limited dynamic range due to the decreasing sensitivity under increased applied pressures. Owing to this disadvantage, the triboelectric tactile sensor has not been extensively employed in smart manufacturing applications where a consistently high sensitivity within the dynamic range is preferred. In order to address this issue, a lightweight, compact, bio-friendly and highly sensitive self-powered triboelectric tactile sensor has been investigated based on the triboelectric effect. By integration of deformable foam layer, triboelectric tactile sensor is able to shift the dynamic range by 76–98 kPa without having to employ gain adjustment circuit board or modifying the properties of the sensor (geometric, materials, etc.). The proposed tactile sensor can be employed in various smart manufacturing applications in which light, self-powered, and high-performance tactile sensors are required to reduce the weight and energy consumption.

A Light Harvesting, Self-Powered Monolith Tactile Sensor Based on Electric Field Induced Effects in MAPbI3 Perovskite.

Organolead trihalide perovskite MAPbI3 shows a distinctive combination of properties such as being ferroelectric and semiconducting, with ion migration effects under poling by electric fields. The combination of its ferroelectric and semiconducting nature is used to make a light harvesting, self-powered tactile sensor. This sensor interfaces ZnO nanosheets as a pressure-sensitive drain on the MAPbI3 film and once poled is operational for at least 72 h with just light illumination. The sensor is monolithic in structure, has linear response till 76 kPa, and is able to operate continuously as the energy harvesting mechanism is decoupled from its pressure sensing mechanism. It has a sensitivity of 0.57 kPa-1 , which can be modulated by the strength of the poling field. The understanding of these effects in perovskite materials and their application in power source free devices are of significance to a wide array of fields where these materials are being researched and applied.

A flexible field-limited ordered ZnO nanorod-based self-powered tactile sensor array for electronic skin.

A tactile sensor is an essential component for realizing biomimetic robots, while the flexibility of the tactile sensor is a pivotal feature for its application, especially for electronic skin. In this work, a flexible self-powered tactile sensor array was designed based on the piezoelectricity of ZnO nanorods (NRs). The field-limited ordered ZnO NRs were synthesized on a flexible Kapton substrate to serve as the functional layer of the tactile sensor. The electrical output performances of the as-fabricated tactile sensor were measured under pressing and bending forces. Moreover, we measured the human-finger pressure detection performance of the tactile sensor array, suggesting that the corresponding mapping figure of finger pressure could be displayed on the monitor of a personal computer (PC) in the form of lighted LED and color density through a LabVIEW system. This as-grown sensory feedback system should be of potential valuable assistance for the users of hand prostheses to reduce the risk and obtain a greater feeling of using the prostheses.

Triboelectric sensor as self-powered signal reader for scanning probe surface topography imaging

We report a self-powered signal reading mechanism for imaging surface topography using a triboelectric sensor (TES) without supplying an external power or light source. A membrane-structured triboelectric nanogenerator (TENG) is designed at the root of a whisker (probe); the deflection of the whisker causes the two contacting surfaces of the TENG to give an electric output current/voltage that responds to the bending degree of the whisker when it scans over a rough surface. A series of studies were carried out to characterize the performance of the TES, such as high sensitivity of 0.45 V mm−1, favorable repeating of standard deviation 8 mV, high Z-direction resolution of 18 μm, as well as lateral resolution of 250 μm by using a probe of size 11 mm in the length and 120 μm in radius. It not only can recognize the surface feature and size but also can perform a surface topography imaging in scanning mode. This work shows the potential of a TES as a self-powered tactile sensor for applications at relatively low spatial resolution.

Human Skin Based Triboelectric Nanogenerators for Harvesting Biomechanical Energy and as Self-Powered Active Tactile Sensor System

We report human skin based triboelectric nanogenerators (TENG) that can either harvest biomechanical energy or be utilized as a self-powered tactile sensor system for touch pad technology. We constructed a TENG utilizing the contact/separation between an area of human skin and a polydimethylsiloxane (PDMS) film with a surface of micropyramid structures, which was attached to an ITO electrode that was grounded across a loading resistor. The fabricated TENG delivers an open-circuit voltage up to -1000 V, a short-circuit current density of 8 mA/m(2), and a power density of 500 mW/m(2) on a load of 100 MΩ, which can be used to directly drive tens of green light-emitting diodes. The working mechanism of the TENG is based on the charge transfer between the ITO electrode and ground via modulating the separation distance between the tribo-charged skin patch and PDMS film. Furthermore, the TENG has been used in designing an independently addressed matrix for tracking the location and pressure of human touch. The fabricated matrix has demonstrated its self-powered and high-resolution tactile sensing capabilities by recording the output voltage signals as a mapping figure, where the detection sensitivity of the pressure is about 0.29 ± 0.02 V/kPa and each pixel can have a size of 3 mm × 3 mm. The TENGs may have potential applications in human-machine interfacing, micro/nano-electromechanical systems, and touch pad technology.