Fabrication of Sustainable Resistive-Based Paper Touch Sensors: Application to Music Technology.

摘要

Building novel Digital Music Instruments (DMIs) requires the use of a variety of sensors to transduce human actions to electronic signals that will control sound synthesis variables. Among them, contact (force/pressure) sensors such as the Force Sensing Resistors (FSR) are the most commonly used in the design of DMIs. Similar commercial sensor designs based on conductive materials also enable to detect position, displacement or flexion. Unfortunately, although commercial sensors can be easily found at electronic resellers, only a few standardised models with predefined sizes, shapes and electric characteristics can be purchased. Moreover, the quality of the sensor appears to depend on their shape and dimension. These limitations have direct implications on the design of novel DMIs, which actually need to be adapted to the existing offer of commercial sensors.;We first began by studying the potential of building paper contact sensors using industrial paper. This type of paper is originally produced to provide optimal colour properties and is not optimised for use as a conductive material. Nevertheless, it has been shown that it provides a very efficient choice for the design of custom sensors. Several sensor prototypes were built using samples of four industrial papers from three main manufacturers (ArjoWiggins (Canson), Fabriano, and PASCO) and have been used in the design of various gesture controllers. In order to verify the electrical behaviour of these prototypes, we developed a special test machine that enabled us to characterise the sensor's properties in terms of repeatability, drift and hysteresis, and to compare the results with commercial sensors.;The second step was to consider how to produce such a paper. Laboratory experiments were performed to evaluate the influence of the papermaking process as well as the chemicals to be added to optimise the retention and formation of a uniform mix of pigments and fibres, enabling the fabrication of a rough, porous, compressible but still elastic material. Papers with various amounts of pigment and different sheet structures were made and characterised in order to evaluate the influence of the paper characteristics onto their electrical resistance. Resulting materials were also characterised with the test machine and compared to other types of resistive materials.;This research contributes to the promotion of alternative solutions for the development of contact sensors. In particular, it shows that conductive paper and inks are an ecological alternative to conducting polymers for producing custom contact sensors. Paper sensors can replace industrial sensors in many applications, as they are equally efficient. Moreover they are recyclable or reusable, flexible and customisable, therefore extending the capabilities of industrial solutions. The production of such a paper will provide researchers with raw materials to produce their own sensors and realise new DMIs, such as the ones presented in this thesis. Apart from their usefulness in acquiring expert musical gestures, paper sensors have potential applications in many other fields such as medical (e.g. as hospital bed sheet), security (e.g. sensitive floors), intelligent packaging, etc.;After various investigations with polymers, textiles, adhesives and glues, we finally chose to focus on conductive paper as a generic material for producing sustainable, flexible and customisable contact sensors. This thesis study presents two directions on paper sensors investigations:;Multi-disciplinary research is a profitable way for creating new technological outputs. Conductive paper can provide new ways of building DMIs at moderate cost and with an environmental-friendly label. Music and arts can in return offer an efficient and sensitive proof-of-work to convince industries that conductive papers have a major potential in other applications.