Micropump For Drug Delivery Research Articles

Study of the effect on flow rate for planar type polymer-based diaphragm piezoelectric actuated valveless micropump for insulin delivery

Micro-electromechanical systems are electrically sensed and actuated mechanical devices that are in micrometre-sized overall dimensions. The microsize of the system enables it to be used in several critical applications including healthcare where the system performance can be precisely controlled. One such application is micropump for drug delivery. Micropumps can be either valve based or valveless. Valve-based micropumps have mechanical check valves to control and deliver drugs through flaps or membranes. In valveless micropumps, the control is made through a diffuser/nozzle arrangement which regulates the liquid flow rate. In this paper, a valveless insulin pump based on piezoelectric actuation made of polymer-based material as diaphragm in planar type is constructed and the dependency of flow rate with material properties and size is studied. The modelling of the pump is carried out using COMSOL Multiphysics by coupling fluid structure interaction (fsi) and piezoelectric (pzd) physics module. The transient response of the flow rate and pressure distribution was studied. The dependency of flow rate with applied voltage, frequency and aspect ratio of the diffuser/nozzle was characterised by various size of the piezo layer and diaphragm layer. The effect on flow rate with polymethylmethacrylate and polydimethylsiloxane with single layer and stacked double layer was characterised. Sinusoidal actuating voltage is applied on piezoelectric material and varied up to a maximum of 180 V, 100 Hz. The simulation result proved that the flow rate can be effectively controlled with the application of appropriate combination of external sinusoid voltage, frequency and aspect ratio of the diffuser/nozzle.

Wireless surface acoustic wave and MEMS-based microsensors

The integration of surface acoustic waves (SAW), microelectromechanical systems (MEMS), and required microelectronics and conformal antennas to realize programmable microsensors suitable for many engineering and biomedical applications will be reviewed in this talk. This unique combination of technologies results in novel conformal sensors that can be remotely sensed by a wireless communication system with the advantage of no power requirements at the sensor site (passive sensor). The required features in many of these applications are high precision, wide dynamic range, and wide frequency range. The MEMS-SAW-based devices presented possess typical advantages of MEMS sensors including the additional benefits of robustness, excellent sensitivity, surface conformability, and durability. After a brief overview of SAW sensors and MEMS, the paper is focused on the design and fabrication of MEMS devices for engineering and medical applications, for example: accelerometer and gyroscopes for automobile, inertial navigation; sensors for pressure, torque, temperature, and strain; health monitoring of structures; ‘‘smart tongue and electronic nose;’’ micropump for drug delivery; humidity, temperature, and ethlyne oxide sensor for hospital sterilization system; microsensors for monitoring bone healing; and pollution and chemical sensing.