Arrayed Force Sensors Made of Paper, Elastomer, and Hydrogel Particles

Autor: Xiyue Zou, Tongfen Liang, Nastassja Lopez, Moustafa Ahmed, Akshitha Ajayan, Aaron D. Mazzeo
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Micromachines, Vol 8, Iss 12, p 356 (2017)
Druh dokumentu: article
ISSN: 2072-666X
DOI: 10.3390/mi8120356
Popis: This article presents a sensor for detecting the distribution of forces on a surface. The device with nine buttons consisted of an elastomer-based layer as a touch interface resting on a substrate of patterned metallized paper. The elastomer-based layer included a three-by-three array of deformable, hemispherical elements/reliefs, facing down toward an array of interdigitated capacitive sensing units on patterned metallized paper. Each hemispherical element is 20 mm in diameter and 8 mm in height. When a user applied pressure to the elastomer-based layer, the contact area between the hemispherical elements and the interdigitated capacitive sensing units increased with the deformation of the hemispherical elements. To enhance the sensitivity of the sensors, embedded particles of hydrogel in the elastomer-based layer increased the measured electrical responses. The measured capacitance increased because the effective dielectric permittivity of the hydrogel was greater than that of air. Electromechanical characterization verified that the hydrogel-filled elastomer was more sensitive to force at a low range of loads (23.4 pF/N) than elastomer alone without embedded hydrogel (3.4 pF/N), as the hydrogel reduced the effective elastic modulus of the composite material by a factor of seven. A simple demonstration suggests that the force-sensing array has the potential to contribute to wearable and soft robotic devices.
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