id5967875 pdfMachine by Broadgun Software - a great PDF writer! - a great PDF creator! - http://www.pdfmachine.com http://www.broadgun.com BBiiooTTISSNe e: 097cc4 - h7h435 nnoolVlolouome g8g Issuyye 5 An Indian Journal FULL PAPER BTAIJ, 8(5), 2013 [687-691] Distinct advantages and novel applications of BioMEMS Ying Jian Chen Research Center for Strategic Science and Technology Issues, Institute of Scientific and Technical Information of China, Beijing 100038, (CHINA) E-mail : [email protected] ABSTRACT KEYWORDS With the great progress of production processÿMEMS have applied to a MEMS; “fundamental lot of areas in recent yearsÿand today they have become BioMEMS; ” devices ÿwhich are comparable with the IC. In this paperÿwe first discuss IC; the main distinct advantages of MEMS as well as the important differences Sensor; between MEMS and ICÿthen some latest research progresses on Biomedical; biomedical, environmental and microfluidics applications of MEMS are Environmental; reviewed. Finally, possible future developments of BioMEMS are Microfluidics; prospected. 2013 Trade Science Inc. - INDIA Application. INTRODUCTION output similar to analog devices. BioMEMS are MEMS that have biological and/or biomedical functions or ap- The acronym MEMS stands for Micro Electro plications. Mechanical Systems with the focal point being the sec- Some of the key advantages of MEMS[3,4] are, “M” • ond (mechanical) and thence ultimately the con- The ability to miniaturize physical interactions to “S”. MEMS are integrated micro-scale systems ’s. cluding nearly the same degree as IC • combining electricalÿoptical or other (magnetic, me- The related ability to reduce the sample-size of chanical, thermal, fluidic, etc.) elements typically fabri- measurands. • cated using conventional semiconductor batch process- The ability to integrate sensing, analysis and re ing techniques, namely, MEMS are macro-engineering sponse in a miniature package. at microscale, they have two main features: (1) design MEMS is not a single product or marketÿbut an structures/devices/systems at micro/nano scale, (2) typi- engineering tool-kit applied to a wide array of markets. cal microsystems involve multiple physical domains. Simpler, but by no means trivial, sensing devices (pres- These systems are designed to interact with the exter- sure, inertial, thermal,etc.) are finding more diverse nal environment either in a sensing or actuation mode to applications and finally emerging into consumer mar- generate state information or control it at a different kets, such as accelerometer and gyroscopic MEMS scale[1,2]. MEMS are the exotic cousins of semicon- devices for the iPhone, Wii and Playstation game con- ductors and integrated circuits (ICs), originally based trollers. Within these MEMS, we typically see integra- on silicon wafer fabrication techniques, but adding the tion, on a single silicon substrate of not just electronic dimensions of space, flexion and continuously variable devices as on the chips, but also mechanical 688 Distinct advantages and novel applications of BioMEMS BTAIJ, 8(5) 2013 FULL PAPER However, three points makes it very different[3,4]: ÿsensors and actuators. In addition to the com- • elements MEMS products are usually application specific, monly present materials in silicon ICs, other materials resulting in a wide range of very different products. • such as ceramics and most recently carbon nanotube, The number of MEMS products will be always less ’s. A good example CNT, arrays are also being incorporated into MEMS. than that for semiconductor IC The resulting microsystems have shown, for a variety ÿunprecedented levels of miniaturization is the inkjet printer. The four inkjet nozzles are op- of applications [5,11] erated using printed circuit boards with tens of other (reliability) and new capabilities . silicon devices. • “unit cell” (like Unlike IC manufacturing, there is no MEMS VERSUS IC the transistor) in MEMS technology. This leads to a more diverse technology base with more devel- MEMS are a class of physically small systems that opment and engineering work. Hence, it is more combine electronic functions with optical, mechanical, expensive and more difficult to maintain MEMS thermal and others. MEMS encompass the process- technology. based technologies used to fabricate tiny integrated Some important differences between MEMS and devices. MEMS are a logical extension of microelec- IC are summarized in TABLE 1. There is also lack of a tronics and IC technology. As an extension of IC tech- stable front-end technology (no Complementary Metal- nology, the production of MEMS devices benefits from Oxide Semiconductor) (CMOS) equivalent) in years of IC manufacturing experience. For instance, MEMS. Moreover, there is a multidimensional interac- technologies such as microlithography, chemical etch- tion space in MEMS, for instance, there is not only ing, vapor deposition, and electroplating can be used electrical connections but also optical connections. to create the microstructures of MEMS. The products MEMS are a very complicated multidisciplinary field, range in size from a few micrometers to millimeters. in which physics, chemistry, materials science, mechanics These devices/systems have the ability to sense the en- and engineering play an important role. In addition, the vironment, process and analyze information, and re- end-product functionality of MEMS is often tightly re- spond with a variety of mechanical and electrical ac- lated to the process used to make it. This can be vividly “one product, one process”. At this point tuators on the micro scale, and generate effects on the expressed as macro scale. the MEMS are completely different with the IC indus- As a manufacturing technology, MEMS has sev- try where so many products share a common process. eral distinct advantages[3,4]: • MEMS technology has the characteristics of inter- TABLE 1 : Important differences between MEMS and IC disciplinary. Its diversity of applications has led to MEMS IC an unparalleled range of devices and synergies Unit Cell No unit cell Transistor Front-end No single stable across previously unrelated fields, for instance, bio- CMOS medicine and microelectronics, semiconductor Technology technology Interaction physics and microoptics. Multidimensional Electrical • Space By MEMS technology and batch fabrication tech- Basic Physics and Multidisciplinary niques, one can produce components and devices Disciplines engineering Process or Many products with higher performance and reliability, such prod- One product, one Fabrication share a common process ucts have obvious advantages with small size, light Technology process weight and low cost. • MEMS technology provides the basis for the fab- Therefore, the current research is evolving toward “MEMS unit” that is not a single “unit cell” (e.g. tran- rication of products that cannot be manufactured a by other methods. Hence, MEMS have become a sistor in IC), but small, specifically designed, compo- universally applicable technology such as IC mi- nents libraries that could be refined over time to be- “standard building blocks” for each MEMS de- come BiicoroTcehicph. nollogy An Indian Journal BTAIJ, 8(5) 2013 Ying Jian Chen 689 FULL PAPER • vice domain. Polymerase chain reaction(PCR) for DNA repli- MEMS technology is a enchanting and far-reach- cation. ing area. It has played and will continue to play a very In particular, pressure sensors in biomedical field vital role in both science and human society. Especially, have the following applications: • it has translated physical properties and material char- Blood pressure sensors. • acteristics into structures and devices that can have a Intracranial pressure sensors. ’s everyday life. • large positive impact on people Pressure sensors in endoscopes. • Sensors for infusion pumps. SOME RECENT APPLICATIONS Main differences between MEMS and BioMEMS OF BioMEMS are summarized in TABLE 2. BioMEMS are being re- searched for possible applications in a variety of areas, Until recently, sensors are a major application for but have already led to multiple applications in the fol- MEMS devices. Today, BioMEMS have become the lowing areas[13-15]: largest and most diverse applications of MEMS de- TABLE 2 : Comparing MEMS with BioMEMS vices. Applications for BioMEMS devices exist in clinical medicine, environmental, biological and chemical analy- MEMS BioMEMS Silicon based Biocompatible Material sis. Applications from one area often overlap with other Material areas. Applications can be broadly placed into the fol- Electrical & Biomolecular & physical lowing categories[12-16]: Mechanical parameter • clinical diagnostics and therapeutics, interface, (electrical,mechanical,optical ) • integration transducer integration environmental applications, Moving part in • Motion medium in passive food safety, and micromachining —— —— substrate microfluidic driving • system active bioprocessing. force MEMS technology is an engineering solution for component • biomedical problems. From component aspect, Detection. • BioMEMS is the research of microfabricated devices Analysis. • for biomedical applications. BioMEMS usually contains Diagnosis. • sensors, actuators, mechanical structures and electron- Therapeutics. • ics. Such systems are being developed as diagnostic Drug delivery. • and analytical devices at diagnostic and analytical de- Cell culture. vices. BioMEMS is expected to revolutionize the field BioMEMS encompasses all interfaces and inter- of medicine. Clinical applications of BioMEMS