Journal of Bioremediation & Biodegradation
Open Access

Abstract

The increasing number of mobile devices and the race to energy sobriety make the decrease of the size of microelectronic systems (MEMS) a major challenge. Today, lithium micro batteries are currently the best solution for high-power and energy applications. Incorporate them into credit cards containing a screen or associate them to electronic sensors for the supervision is the challenge which raises international companies such as ST Micro Electronics. However, these micro batteries contain some lithium metal which can be dangerous if the metallic lithium is in contact with water or humid air. In addition, the substance can spontaneously ignite in the contact of the humidity. So, in order to avoid the problems of safety, we absolutely have to protect the lithium contained in our micro batteries using an encapsulation layer. Polymeric encapsulation has the advantage, compared with other materials (ceramic, metal), to present a moderate cost of shaping and a low weight. However, such systems of encapsulation are insufficient to guarantee a satisfactory life cycle of components. Indeed, in the presence of humidity or important temperature variation, the mechanical assemblies can be weakened and engender an irreparable break. Our project is thus to develop thin encapsulation layers of polymers based on natural rubber. The interesting physical and chemical properties of such polymers represent an attractive alternative to existing packaging materials. Moreover, in addition to their barrier properties against water and air, these polymers are known to be ecological, very flexible and have a good elasticity. Diacrylate oligoisoprene derived of natural rubber is associated with a thermal initiator known for its capacity to crosslink a large range of polymers. The process consists of forming a thin film by dip coating a substrate into a polymer/ di-sulfonyl azide mixture and then thermally anneal the film up to a temperature at which the sulfonyl azide decompose. The effects of both the selected annealing temperature, the heating rate and the reaction time were investigated using Fourier transform infrared spectroscopy and Raman spectroscopy. A full analysis of the vibrational spectra provides significant information regarding the thermal reticulation. Our investigations allowed us to determine both the kinetics of thermal cross linking and the main parameters that can help to develop industrial thermal process. This project is realized in collaboration with ST Micro Electronics and applications in micro batteries will be discussed.

Biography

Email: kenza.ayche@live.fr