H. Grande

Polypyrrole-based conducting hot melt adhesives for EMI shielding applications

Abstract Intrinsically conducting hot melt adhesives (ICHMAs) have been developed, based on polypyrrole (PPy) blends, for use in electronic and telecommunication applications requiring shielding against electromagnetic interference (EMI). These advanced materials have been formulated to exhibit significant EMI shielding effectiveness (SE) while retaining the superior properties of conventional hot melt adhesives. The conductivity properties, adhesion characteristics and both near- and far-field EMI SE behaviour of these ICHMAs at room temperature are investigated as a function of PPy content. The environmental stability of the conductivity is also reported. Potential use of such new materials in current and future electronic applications is anticipated.

Functional patterns obtained by nanoimprinting lithography and subsequent growth of polymer brushes

In this work the growth of polymer brushes was combined with nanoimprint lithography (NIL) in order to obtain new functional nanopatterns. First, a functional thermoplastic methacrylic copolymer poly(methyl methacrylate-co-2-bromoisobutyryl-oxy-ethyl methacrylate) was synthesized. This copolymer was successfully patterned by NIL using a silicon stamp at 160 °C and 60 bar. Next, hydrophilic polymer brushes based on poly(3-sulfopropylmethacrylate) and hydrophobic polymer brushes based on a poly(fluorinated methacrylate) were grown on the imprinted surfaces. The surface properties of the patterned polymer were accordingly modified and, as a consequence, the water contact angle was modified from 80.3° to 32.5° in the case of the hydrophilic brushes and to 118.1° in the case of the hydrophobic brushes. As an application we demonstrated the use of hydrophobic polymer brushes in order to modify the surface of polymeric stamps for NIL with self-demoulding properties.

Distributed Pressure Sensor Based on Electroactive Materials for Automotive Application

The development of distributed pressure sensors based on conducting polymers for automotive application is described. These pressure sensors can be placed on large surfaces due to its flexibility and low cost. As a consequence, pressure data are obtained not only from some discrete points but also from continuous surface points. 256 of these sensors have been placed on an automotive seat, giving the so-called “smart automotive seat”. These sensors are able to provide information about the person on the seat (adult, child, size, weight, etc.). This information can be used by the central electronic system in the vehicle for activation and modulation (or deactivate if necessary) of security systems (airbag, seat belt’s prestress system, etc.). Response time is lower than 2 milliseconds, and it works in pressure ranges of 0.05–10 kg/cm2, showing a lifetime of more than 10 millions of actuations.