BioMEMS Emerges

"BioMEMS is much more than a subset of MEMS, it is rapidly becoming a field unto itself, uniquely identified by its dimensions, materials, engineering, and physics," says SPIE member Steven Saliterman, chair of the Department of Medicine of Methodist Hospital and adjunct assistant professor at the University of Minnesota, both in Minneapolis, MN.

"Silicon, glass, and polymers may be microfabricated with techniques ported over from traditional MEMS technologies, including integrated circuit fabrication techniques. However, bioMEMS also entails polymer selection, fabrication, and surface modification, as well as uniquely incorporated biological materials. Microfluidics, electrokinetics, and detection strategies are all at the heart of bioMEMS systems.

"Perhaps what most identifies bioMEMS as an emerging field is the multidisciplinary background of students taking introductory bioMEMS courses, including biomedical, electrical, chemical, and mechanical engineering graduate students, material science specialists, and health-related sciences students. BioMEMS is the platform upon which nanotechnology will be delivered."

Saliterman enthusiastically predicts that our lives will dramatically change over the next 10 years as a direct result of bioMEMS technology. "Research, laboratory medicine, point-of-service care instruments, diagnostic and surgical tools, medications, and implanted devices may all incorporate bioMEMS," says Saliterman. "Traditional medical devices will flourish with bioMEMS at their core, and a new breed of medical microdevices, unimaginable even a few years ago, will emerge and become dominant.

"Imagine taking a pill," he muses, "that contained multiple antibiotics, but only the required one is released from the pill matrix, hence avoiding unnecessary treatment. Imagine a heart, liver, or kidney grown not from stem cells, but instead fabricated layer by layer in what might be termed large-scale bioMEMS integration. The list of possibilities is endless."

When asked what professions would be most affected by the impending upsurge of bioMEMS, Saliterman paints the future with a wide brush.

"In addition to the aforementioned students, bioMEMS is important to practicing engineers and health sciences workers. Physicians, nurses, and hospital administrators need to follow the technology and input on its development. The general public must also be made aware of the new technology, for it will bring some surprising alternatives to conventional therapy.

"Healthcare and manufacturing industry leaders, politicians, and government officials should also track bioMEMS developments. Ultimately it is the payor (patient, insurance, Medicare) who will decide the fate of even the most promising medical intervention. BioMEMS must prove itself as an effective, safe, and cost-effective alternative to traditional methods."

On a darker note, Saliter-man addresses both the good and bad of bioMEMS potential in defense and security. Although he says homeland security will benefit from novel biochemical detectors for explosives and biohazards, he warns, "BioMEMS brings the potential for desktop nucleotide assembly, and hence synthesis of genetic material, including viruses and bacteria. It is likely that within 10 years nearly any individual with minimal biomedical training will be able to synthesize viable viruses for which we have no immunity, causing widespread morbidity and mortality. A worldwide effort must be under- taken now to restrict access to potentially harmful genetic sequencing data and certain technologies."

In either case, the impact of bioMEMS on the next 10 years will undoubtedly be dramatic.

For more on bioMEMS, check out Saliterman's Fundamentals in BioMEMS and Medical Microdevices, available now from SPIE Press.

Based on the author's course on bioMEMS at the University of Minnesota, this 600-page book is an introduction to the science and a survey of the state of the art.

Topics include microfabrication of silicon, glass, and polymer devices; microfluidics and electrokinetics; sensors, actuators, and drug delivery systems; micro-total-analysis systems and lab-on-a-chip devices; detection and measuring systems; genomics, proteomics, DNA, and protein microarrays; emerging applications in medicine, research, and homeland security; and packaging, biocompatibility, and ISO 10993 testing.