Biomedical Microdevices: From Mechanical Structures to Implantable Sensors
Professor Mark G. Allen
School of Electrical and Computer Engineering
Georgia Institute of Technology
Atlanta, GA 30332-0250 USA
The use of microfabrication techniques to create mechanical structures and transducers, potentially in addition to electronic devices, has now developed into industrial practice: a manufacturing technology for microelectromechanical systems, or MEMS. Reflecting their manufacturing roots, MEMS typically share many features with integrated circuitry: batch fabrication economics, capability of high volume manufacture, and the potential to create devices on the micron scale or smaller (or larger overall devices with micron-scale or smaller enabling features). Although major applications of MEMS manufacturing technology are high-volume industrial and automotive sensors, these same manufacturing characteristics have been more recently exploited in the biomedical arena, where the high volume manufacture capability meshes well with disposable or one-time use, and the small size scales mesh well with many biological systems. However, some of the challenges in adapting 'traditional' MEMS technologies to these new applications include development of fabrication techniques for biologically-appropriate materials, biomedical microdevice packaging, and system partitioning issues, including integration with circuitry and supply of power. In addition to the technical challenges, the MEMS engineer working in these fields must interface efficiently with the medical community, understanding their needs and constraints, to produce useful devices. This talk will discuss the challenges of biomedical device fabrication and implementation, and illustrate through example how these challenges were overcome for selected biomedical microdevices: three-dimensional microvasculatures for microfluidic perfusion of tissue; biodegradable microneedles and interlocking biodegradable mechanical structures for drug delivery and microsurgery; and wireless implantable microsensors (currently in FDA trials) for monitoring of physical properties internal to the body.
Mark G. Allen holds the J.M. Pettit Professorship in Microelectronics in the School of Electrical and Computer Engineering at the Georgia Institute of Technology, and a joint appointment in the School of Chemical and Biomolecular Engineering. He joined Georgia Tech in 1989, after receiving the Ph.D. (1989) in Microelectronics and S.M. (1986) in Chemical Engineering from the Massachusetts Institute of Technology, and B.S.E. and B.A. degrees in Electrical Engineering, Chemical Engineering, and Chemistry from the University of Pennsylvania. Professor Allen's research interests are in the area of microfabrication and nanofabrication technology, with emphasis on new approaches to fabricate structures, sensors, and actuators with characteristic lengths in the micro- to nanoscale from both silicon and non-silicon materials. Examples include micromagnetics, bioimplantable microdevices, high temperature sensors, small-scale power generation, compact actuators, fluidic microvasculatures, and the use of microstructures to create nanostructures.