Current Projects
After spending five years working on microdevices for medical and health science applications, I have been working on multisensory communications and how to use technology to better interact with others as well as with the environment. My journey has now taken me to the Imagineering Institute in Malaysia.
Magnetic Dining Table
The magnetic dining table is the first project that I joined while working at the Imagineering Institute. I started my work by improving the model of the existing system and creating an improved control system. These improvements led to stable levitation of food, which also helped to create it as a display for the Digital Food Exhibit at the Singapore Science Center.
Previous Projects
My work during my PhD primarily involved microfabrication and development of novel technologies for use in medical research and medical devices. This is a brief overview of some of the technologies that have been developed in conjunction with my time at the Cell Biomechanics Laboratory.
Magnetic Nanowires
My initial exposure to the world of microtechnology was to develop magnetic nanowires. I followed interesting and basic procedures to create magnetic nanowires using simple and ordinary supplies following this guide. The process of making nanowires was something that I was able to initiate within my first few weeks of working in the lab, and I would soon discover the rarity of easy success in science. I generally stuck to templated deposition of nickel and iron nanowires, as that enabled the use of a rudimentary system using a copper plate, Whatman’s Adodisc filters, plating solution, conductive wire, and a single AA battery. Potentiostats are often used to control the grain structure and size of nanowires, but a battery is perfect for creating small magnets that can be used for a number of applications. Ultimately, this work never made it into any of my research papers, but showing off the nanowires that I made was a highlight of every tour of my workbench.
Magnetic Actuation
One of the many benefits of using magnetics in microdevices is the ability to create force at a distance. This ability can be exploited in microfluidic devices to investigate fluids and manipulate the environment without introducing potential weak points to the channels. The Cell Biomechanics Lab has often used microposts with diameters of 2-4 µm, and heights of 5-10 µm, so it was natural for me to start work on these posts. Although I managed to move the microposts, I found that a larger post was easier to manipulate with a higher consistency. My work around mangetic actuation sought to investigate the properties of fluids within a microfluidic well. I developed a model to describe how the post moved, and moved the post with an electromagnetic while monitoring its location through a microscope. The motion of the post with respect to the force from the electromagnet can be used to describe the properties of the fluid in the well.
Magnetic Sensing
Another advantage of magnetics is the ability to sense motion at a distance with embedded material and low-cost systems. A primary focus of my research has been developing novel methods to sense magnetic material within microfluidic systems. Although the material within microfluidic systems tends to produce small magnetic field effects, a dynamic system lends itself to sensing with the aid of filters to hone in on the signal. I developed a system to monitor heart tissue twitch forces through the use of giant magnetoresistive sensors placed below a tissue culture dish. The system successfully monitored six tissues simultaneously in real-time to discover the effects of drugs as they were added to affect the tissues. This system can be the base of a drug-testing program to reduce dependence on high-cost and time-consuming microscopes and create and easy and accessible way to monitor tissue twitch forces.
Microfabrication
Although my published papers have been focused on work that did not require work in the clean room, much of my unpublished work involved time in the clean room fidgeting with all sorts of high-tech technology. I attempted some builds of custom magnetoresistive sensors using magnetron sputtering, but the control on the sputtering system was much less than with other methods. I also pushed the limits on aspect ratio and height for posts using both photolithography with SU-8 and with deep reactive ion etching (DRIE). One project that showed promise was the development of posts with high aspect ratios using polystyrene instead of PDMS. The posts never achieved enough flexibility to see forces of normal cells, but the process would have enabled more applications for force measurements of cells.