An optical-based multipoint 3-axis pressure sensor with a flexible thin-film form

Abstract

Multipoint 3-axis tactile pressure sensing by a high-resolution and sensitive optical system provides rich information on surface pressure distribution and plays an important role in a variety of human interaction–related and robotics applications. However, the optical system usually has a bulky profile, which brings difficulties to sensor mounting and system integration. Here, we show a construction of thin-film and flexible multipoint 3-axis pressure sensor by optical methods. The sensor can detect the distribution of 3-axis pressure on an area of 3 centimeter by 4 centimeter, with a high-accuracy normal and tangential pressure sensing up to 360 and 100 kilopascal, respectively. A porous rubber is used as a 3-axis pressure-sensitive optical modulator to omit the thick and rigid focusing system without sacrificing the sensitivity. In addition, by integrating thin and flexible backlight and imager, the sensor has a total thickness of 1.5 milimeter, making it function properly even when bent to a radius of 18 milimeter.

Flexible Three-Dimensional Force Tactile Sensor Based on Velostat Piezoresistive Films

“…Although conductive nanomaterials and flexible substrates provide an important foundation for the preparation of flexible 3D force tactile sensors, the manufacturing of sensors exhibiting high sensitivity, excellent cycling stability, and fast response based on simple and low-cost preparation processes still faces huge challenges. Based on their sensing mechanism, flexible 3D force sensors can be classified into piezoresistive [20][21][22], piezoelectric [23][24][25], capacitive [26][27][28], triboelectric [29][30][31], and optical [32] sensors, which all generate different types of signals under mechanical stimuli, such as pressure, stretching, bending, and torsion. Compared with the common capacitive and piezoelectric mechanisms, piezoresistive sensors exhibit a higher sensitivity, faster dynamic response, and larger measurement range.…”

Recent advances in multimodal sensing integration and decoupling strategies for tactile perception

“…At present, tactile sensing predominantly involves the measurement of mechanical stimulus such as pressure, strain, touch, and vibration, as well as temperature and humidity. The previous literatures propose various mechanisms for the sensing of mechanical stimulus, including piezoresistive [13,14], piezocapacitive [15][16][17], piezoelectric [18][19][20], triboelectric [21][22][23][24] and optical mechanisms [25][26][27]. Temperature sensing widely utilizes thermo-resistive [28][29][30] and thermoelectric [31] response.…”

Monitoring Soft Shape Surface Deformation via Optical Images for the Distinction of Contact State

“…In the past few decades, tactile sensors have flourished in many fields, such as soft robotics, electronic skin, and flexible electronics. [1][2][3][4] In these applications, interface soft touch has attracted extensive attention, which is considered to be effective in achieving human-like interaction effects. [5][6][7] Soft-elastic interfaces offer the opportunity to capture multimodal physical information, and the external stimuli (such as pressing, sliding, and twisting) could be decoupled by analyzing the change in these physical signals.…”