A review of various actuation methods in micropumps for drug delivery appliactions

Microelectromechanical systems (MEMS) have been used in diverse applications, from display technologies to sensor systems to optical networks and in medical fields for micropumps in drug delivery systems. MEMS are attractive for many applications because of their small size and weight, which allow systems to be miniaturized. On-chip actuation of microsystems has been a particularly challenging aspect of MEMS development. Common macro-level actuation approaches, such as hydraulics, pneumatics, electric motors, internal combustion engines and turbines, are either too difficult to fabricate at the micro level or do not work well at that scale. Electrostatic attraction is one approach that has been widely used for actuation of microsystems. While electrostatic actuation is suitable for many applications, some systems require either lower voltages or higher output forces. In this paper a comparison of some commonly used MEMS actuation mechanisms for micropumps in drug delivery systems are compared. After the comparison it is proven that electrostatic actuation has been commonly adopted due to the enormous advantages it possesses over the other actuation mechanisms. Electrostatic actuation is more popular in micropump application than others due to its high compatibility with micro-fabrication processes, low power consumption, simple structure and quick response.