In this paper we develop vacuum-actuated polyimide bi-stable actuators using buckled diaphragms for applications in the field of MEMS. The fabrication process involves a single mask step and DRIE etch step to fabricate the buckled bi-stable diaphragms. Compressive stresses in a companion thermal oxide layer provide pre-stress in the polyimide mechanical films that initiates diaphragm buckling u...

In this chapter we describe the preparation of polyimide thin films by physical vapour deposition and comment on their potential application as a pure material or a thin layer matrix for producing nanocomposite layers. Their superb properties, such as a low dielectric constant, high thermaland photo-stability, high chemical resistance and high optical transmittance predetermine their widespread...

This research focuses on the synthesis and characterization of a piezoelectric (β-CN)APB/ODPA polyimide. The remanent polarization and piezoelectric d31 and g33 coefficients are reported to assess the effect of synthesis variations. Each of the materials exhibits a level of piezoelectricity which increases with temperature. The remanent polarization is retained at temperatures close to the glas...

Three new polyfunctional amines were synthesized. Polyimide films containing varying amounts of the amine crosslinking agents were prepared. Their thermomechanical properties were compared with those of control film samples prepared from difunctional amines. The effect of crosslink density on isothermal weight loss, polymer softening, and glass transition temperature is discussed. EFFECTS OF MU...

Preliminary work using polyimide (PI) as the polymer matrix for permselective membranes is reported in this paper. The excellent adhesion of polyimide may be helpful in extending solid-state chemical sensor lifetimes. Electrochemical performance and adhesion to S&N, of these membranes is compared to that of conventional PVC-based membranes.

This thesis focuses on studies of nano-scale materials in electronic packaging applications with respect to following aspects: surface analysis of nano-scale oxide of lead-free solder particles, and thermal performance and mechanical property studies of nano-scale fiber and metal composite-based thermal interface materials. The composition and thickness of the solder oxide have a direct impact ...

Micromachining technologies have been used to manufacture neural microelectrodes for roughly a decade. One promising approach utilizes polyimide as a flexible and light-weighted substrate that carries electrode contacts, tracks, and connector pads. Beyond encouraging results, mainly gained in acute animal trials and in vitro tests, the reliability of this technology needs to be proved. The pres...

Here, we developed high-efficiency (>99.5%) polyimide-nanofiber air filters for the high temperature PM2.5 removal. The polyimide nanofibers exhibited high thermal stability, and the PM2.5 removal efficiency was kept unchanged when temperature ranged from 25-370 °C. These filters had high air flux with very low pressure drop. They could continuously work for >120 h for PM2.5 index >300. A field...

Some applications in microelectronics call for freestanding polyimide films with fine metallic wiring patterns that are thinner than commercially available copper-clad polyimide sheets, which are typically greater than 25 pm in thickness. This work describes a laserassisted technique to fabricate freestanding multilayer thin-film wiring with polyimide dielectric insulating layers that are less ...