Microelectromechanical Systems (MEMS)

We seek to understand and exploit interesting characteristics of smart materials, such as shape-memory-alloy and shape-memory-polymers as well as hybrid combinations of them with unusual classes of micro/nanomaterials, in the form of microdevices. Our aim is to control and apply these devices in various applications including in automation, microrobotics and biomedical areas. Our work combines fundamental studies with forward-looking engineering efforts in a way that promotes positive feedback between the two. Our current research focuses on smart materials for robotics structures, microfluidic devices, and micro/nano electromechanical (MEMS/NEMS) systems. These efforts are highly multidisciplinary, and combine expertise from nearly every traditional field of technical study.

Projects:

1. Wireless Implantable Drug Delivery Device Based On Shape Memory Alloy Microactuator

This project propose a novel out-of-plane microactuator based on a bulk-micromachined SMA coil with a built-in heater that is controlled wirelessly using RF magnetic fields. The out-of-plane SMA coil will bemicrofabricated through a planar process and self-assembled by locally controlled bending of the coil structure. The SMA coil acts as both a resonant heater circuit, which receives RF power wirelessly for heat generation, and avertical actuator structure. This monolithic approach is aimed to reduce the overall size of the actuator and heat loss associated with the hybrid device, while eliminating the need for bonding and assembly processes for SMAintegration. Direct wireless heating of the SMA coil is expected to improve temporal response and reduce the temperature gradient of the actuator. 


2. MEMS Thermopile Wearable Power Harvesting Device


This project focuses the design of micro-power generators harnessing using MEMS technology. This indirectly lead to the invention of alternative self-powered harvesters that are smaller in size and implantable so as to augment or surrogate the conventional large scale energy transducers, and to reduce the usage of main power supplier. Here, the main inspirations are to add simplicity and easiness into the daily life, less cost, and respecting the nature of ecosystem. Subsequently, implying ambient energies and radiations can be a great alternative as they are ecological friendly and renewable. Also in that manner, the life durations and capabilities of such energy scavenging systems can be upgraded. Similarly, small scaled thermoelectric power plants are very useful for easy powering or charging of mobile electronics even at remote areas without expecting a main power supplies. So, the systems are commonly applied as wireless sensor networks. Besides, such self-powered devices also encompass several extra benefits that may attract more attentions towards their systems viability. Micro-thermoelectric generator directly converts thermal energy into potential differences. It is a low cost generator with reliable energy source and has no moving blocks thereby, easily scalable. Moreover, it can be used to recycle wasted heat energy, so it also endows to a healthier atmosphere. In this project, several important elements such as, flexibility of the thermo-electric power harvesting device, portability, low cost factors, and best possible thermo-electric materials that provides highest output power will be analyzed.



3. Wireless flow-control method for microfuidic application


This project demonstrates the flow controlled functionality using RF wireless mechanism for lab on chip (LOC) device. This approach aims to control the flow switching sequence for centrifugal microfluidic application during spinning process, where a conventional valving principle is hardly to be implemented. In addition, the heat induced from the RF heating can be utilised as an actuation mechanism to eject a controlled amount of dosage to the targeted area, which further eliminates the requirement of batteries and active circuitry in micropump application.



4. Integration of Shape-Memory-Alloy Actuator and Its Application as Micromanipulator

Bulk shape-memory-alloy actuators have great potential to be used in various microdevices. Previous studies show that this material is very attractive due to its very large force, high mechanical robustness with a simple structure and biocompatibility. This research present a novel shape memory alloy micromanipulator through applying an integration of multiple shape memory alloy microactuators. the micromanipulator will be developed using monolithic approach. Due to the challenges exist in developing the integration and the monolithic approaches into micro-electro-mechanical systems (MEMS) fabrication, the success of bulk shape memory alloy in MEMS is rather limited today. The successful outcomes of this research are expected to promote advances in these device technologies in biomedical fields and beyond. This report discusses the important measures that are necessary to develop the shape memory alloy micromanipulator, and then reviews on the challenges and status of current strategies.