A Bimetallic Thin Film Actuated Micro Liquid Delivery System (LDS)

Principal investigator: Mr. Chen Mei Ma

Co-investigator: A/Prof Thomas Gong Haiqing


Date started: 07/1998

Date completed:


To design and develop a Micro Liquid Delivery System for medical use.

Bimetallic effect

Deflection caused by mismatch of thermal expansion of two layers of materials.

Structure of Micro LDS

The Micro LDS consists of four major subsystems:

  1. A bimetallic composite membrane microactuator.
  2. Two micro check valves
  3. Four micro flow rate sensors integrated in the bimetallic composite membrane.
  4. An electrically isolated meander type resistor (sandwiched in bimetallic membrane)

pic 1

Working Principle (one cycle of pumping)

The working of Micro LDS includes two steps:

  1. the bimetallic thin film is heated, an upward deflection of the membrane occurs, negative pressure generates inside the chamber. Thus inlet valve opens, fluid flows in the chamber.
  2. the bimetallic thin film is cooled, it bends down, positive pressure generates. Outlet valve opens and fluid flows out.

pic 2

Main Advantages

Nice SEM!


Last updated: 20.10.99