Tactile Sensors Based on Conductive Polymers

This paper presents results from a selection of tactile sensors that have been designed and fabricated. These sensors are based on a common approach that consists in placing a sheet of piezoresistive material on the top of a set of electrodes. We use a thin film of conductive polymer as the piezoresistive mate¬rial. Specifically, a conductive water-based ink of this polymer is deposited by spin coating on a flexible plastic sheet, giving it a smooth, homogeneous and conducting thin film. The main interest in this procedure is that it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work we present results from sensors made using two technologies. Firstly, we have used a flexible Printed Circuit Board (PCB) technology to fabricate the set of electrodes and addressing tracks. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with screen printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. The intense characterization provides us insights into the design of these tactile sensors.This work has been partially funded by the spanish government under contract TEC2006-12376-C02

Composites of carbon nanotubes and conducting polymers as electrodes of supercapacitors

2 Figures, 1 Table.-- Work presented at the Carbon '05, Gyeongju, South Korea, 3-7 July 2005.Composites of single wall carbon nanotubes (SWNTs) and polypyrrole (PPy), and multiwall carbon nanotubes (MWNTs) and polyaniline (PANI), were prepared by in situ chemical polymerization. Electrodes for supercapacitors were formed by pressing the PPy/SWNT and PANI/MWNTs. To evaluate the specific capacitance values of the carbon nanotube/conducting polymer electrodes, galvanostatic charge-discharge cycling tests and cyclic voltammograms were performed. Cyclic voltammograms of the nanocomposites present a rectangular shape, showing good capacitive behaviour. In the galvanostatic experiments, composites also show good characteristics of capacity and low resistance. The nanocomposite material electrodes show higher specific capacitances than the as grown carbon nanotube electrodes and higher stability than the conducting polymer

Improvement in the Ppy/V2O5 hybrid as a cathode material for Li ion batteries using PSA as an organic additive

With the aim of improving the electrochemical properties of this candidate cathodic material for lithium ion batteries, a vanadium oxide (V2O5) and polypyrrole (Ppy) hybrid was prepared using pyridinesulfonic acid (PSA) as additive. The hybrid synthesis has been carried out in the literature by chemical polymerization of pyrrole in the host inorganic matrix, using the V2O5 dispersed in an acidic solution as an oxidizing agent. In this work the hybrid has been synthesised with PSA giving good results compared to other samples of the pristine V2O5 and to the Ppy/V2O5 hybrid without additive. An improvement of about 20% in the charge storage capacity has been achieved. The reasons for this improvement are discussed and analyzed using different experimental techniques. The hybrid material has the added advantage of an improved performance without the addition of any binder or conducting element as a cathode in a lithium ion battery.We thank the Spanish Ministry for Science and Technology (MAT2002-04529-C03) for financial support.Peer reviewe

Influence of acids in the Ppy/V2O5 hybrid synthesis and performance as a cathode material

Vanadium oxide (V2O5) is a candidate as cathodic material for lithium ion batteries. With the aim of improving the electrode performance, Polypyrrole (Ppy) has been proposed as binder and conducting element in the oxide structure. The hybrid synthesis has been carried out in the literature by chemical polymerization of Pyrrole in the host inorganic matrix, in some cases using the V2O5 dispersed in an acidic solution as an oxidizing agent. The hybrid material can be prepared using different acidic solutions that can influence the polymerization process affecting the electrochemical properties of the final hybrid material. The reasons and consequences for this influence are discussed and analyzed using different experimental techniques.We thank the Spanish Ministry for Science and Technology (MAT2002-04529-C03-02) for financial support.Peer reviewe