Proposal of A New Bimorph Piezoelectric Actuator for Blood Extraction Pump in Health Monitoring System

Abstract

Health monitoring system equipped with blood extraction pump is one of the important problems for new medical technology to support the advanced age society. In this paper, a new piezoelectric actuator for blood extraction pump was proposed to increase volumetric change in pump. We devised the geometry of piezoelectric actuator with some slits that allows the stretching and contracting deformation in in-plane direction to create large deflection in outof-plane direction. Focusing on a disc-type bimorph plate with some slits, the deformations under static electric load have been analyzed by finite element method with consideration of two geometric parameters, length l and width w of slits. The computational results indicated that the deformation of bimorph actuator changes from complex mode to single mode according to increase of slit length, and that single mode presents remarkable increase of deflection under surrounding-fixed condition. And then, a bimorph actuator with 4 slits l = 2.0, w = 0.5mm has been manufactured as an experiment. As a result, a developed actuator was proved to increase the deflection under dynamic electric load compared with a conventional bimorph actuator without slits.

Development of a New Piezoelectric Actuator with Slits

“…The slit of piezoelectric element has two workings. One is to reduce the overall bending rigidity of actuator, and the other is to allow the in-plane deformation under fixed conditions [11]. This paper targets a disk-shaped piezoelectric actuator and focuses on two types of slit, which are the outside slit and cross slit.…”