Flexible pressure sensor on polymeric materials

In this work we investigate the use of polymer materials as a basis for fabrication of a novel type of pressure sensors for use in medical diagnostics. Experience with solid-state micro-electromechanical systems (MEMS) sensors has proved them to provide a number of desirable characteristics in sensory applications, including miniaturization and low production cost. However, owing to their rigidity, and bio-incompatibility, the solid-state sensors are not ideally suited for applications in biomedical implants and in-vivo diagnostics. They often require extra encapsulation protection, and thus diminishing their sensitivity and selectivity. Polymeric materials such as polyimide have been for a number of years utilized to manufacture flexible printed circuit board (FPCB) and membrane switches used in computer keyboards. Related work on polymer electronics has shown feasible the fabrication of micro sensors using polymer materials. In this paper we show that combining the polymer thick-film (PTF) technology with the MEMS micromachining process yields a workable platform for the realization of a flexible sensor for pressure measurements. We will show simulation results that establish the validity of the model and which will confirm the promise that these devices hold for future biomedical instrumentations. Recent sensor research by another group demonstrated a multi-model tactile sensor which consists of hardness, temperature, and thermal conductivity sensing features, all combined and built on a polymer substrate [1] and [2]. Advantages of using polymer materials include flexibility, biocompatibility, robust characteristics, reduced fabrication complexity and reduced production costs, as well as the use of environmentally friendly manufacturing.