18 May 2009 Tactile sensors based on conductive polymers
Author Affiliations +
This paper presents results from a few tactile sensors we have designed and fabricated. These sensors are based on a common approach that consists of placing a sheet of piezoresistive material on the top of a set of electrodes. If a force is exerted against the surface of the so obtained sensor, the contact area between the electrodes and the piezoresistive material changes. Therefore, the resistance at the interface changes. This is exploited as transconduction principle to measure forces and build advanced tactile sensors. For this purpose, we use a thin film of conductive polymers as the piezoresistive material. Specifically, a conductive water-based ink of these polymers is deposited by spin coating on a flexible plastic sheet, giving as a result a smooth, homogeneous and conducting thin film on it. The main interest in this procedure is it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work we present results from sensors made with two technologies. First, we have used a Printed Circuit Board technology to fabricate the set of electrodes and addressing tracks. Then we have placed the flexible plastic sheet with the conductive polymer film on them to obtain the sensor. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with a screen printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. There is a very interesting difference with the other sensors, that consists of the use of an elastomer as insulation material between conductive layers. Besides of its role as insulator, this elastomer allows the modification of the force versus resistance relationship. It also improves the dynamic response of the sensor because it implements a restoration force that helps the sensor to relax quicker when the force is taken off.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Julian Castellanos-Ramos, Julian Castellanos-Ramos, Rafael Navas-Gonzalez, Rafael Navas-Gonzalez, Haritz Macicior, Haritz Macicior, Estibalitz Ochoteco, Estibalitz Ochoteco, Fernando Vidal-Verdú, Fernando Vidal-Verdú, } "Tactile sensors based on conductive polymers", Proc. SPIE 7362, Smart Sensors, Actuators, and MEMS IV, 73620G (18 May 2009); doi: 10.1117/12.821627; https://doi.org/10.1117/12.821627

Back to Top