A Methodology for the Development of Low-Cost, Flexible Touch Sensor for Application in Assistive Technology

Assistive technology is becoming disruptive to tackle with real needs of frail users, with particular regard to tools supporting the user-environment interaction. To such aim, a real need emerges of user interfaces which are designable on the user needs and easy-to-be adapted to real working conditions. In this article, a methodology for the development of a touch sensor for application in the field of assistive technology is investigated. The touch sensor aims to be flexible, adaptable, and insensitive to the working surface (such as chair and sofa arms, tables, and beds), customizable to user needs, and low cost. In particular, this article deals with the design flow of the device, strongly supported by rigorous modeling of the sensor behavior, the implementation of the sensor prototype by inkjet printing technologies, and the measurement of its main metrological characteristics. The device working range is of millimeters of compression, while the average responsivity and the resolution are 0.140 pF/mm and 0.36 mm, respectively. The sensor exhibits a suitable span-to-resolution, which demonstrates the appropriateness of the solution proposed to tackle the real needs in the application context above mentioned.