Biomedical Engineering Reference
In-Depth Information
7
MEMS,MOEMS,Nano,and
Bionanotech nologies
7.1 Introduction
The simple distinction between the terms micro-electro-mechanical systems
(MEMSs) and nanotechnology is the size of the devices: MEMSs typically range
between millimeters down to microns and nano devices are on the nanometer
scale. Quoting an excellent set of definitions from SmallTech Consulting [1]:
MEMS is the integration of a number of microcomponents on a single
chip which allows the microsystem to both sense and control the envi-
ronment. The components typically include microelectronic integrated
circuits (the “brains”), sensors (the “senses” and “nervous system”), and
actuators (the “hands” and “arms”). The components are typically inte-
grated on a single chip using microfabrication technologies similar to
those used for integrated circuits.
Nanotechnology takes advantage of the observation that at the
nanoscale, properties of materials change. Nanotechnology is that array
of technologies that use properties of materials that are unique to struc-
tures at the nanoscale.
A Richard Feynman presentation in 1959 discussed material fabrication
“from the atom up,” leading to the debate regarding the concept of molecular
manufacturing and molecular nanotechnology. The classic Drexler-Smalley
debate focused on the feasibility of constructing molecular assemblers
[2]. Multidisciplinary efforts continue to pace the complementary fields of
MEMS, MOEMS, nano, and bionanotechnology, with exponential growth
upon exponential growth, advancing toward Ray Kurzweil's projected “sin-
gularity” around the year 2040. Nanomaterials for biology now include
quantum rods and dots (CdSe, CdTe, and CdHgTe), non-heavy-metal-based
quantum dots (InP, CuInS 2 , silicon, magnetic nanoclinics, silica nanopar-
ticles, metallic [gold and silver] particles and rods, and rare-earth-doped
nanophosphors [Er and Tm:NaYF 4 ]) [3].
A significant segment of the MEMS market is that of MOEMS—optical
MEMS—partly a result of the fusion of computing and signal processing
with photonics and communications—including the marriage of optics and
semiconductor micromachining and devices—playing heavily in the lab on a
chip concepts for biomedicine. Certainly, the time is ripe for the convergence
 
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