Defense Intelligence Reference Document Biosensors And A Survey Of The Present Field

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The Neural Probe chip enables precise bi-directional positioning of the microelectrodes
in the brain with a step resolution in the order of 8.8 μm. The thermal microactuators
allow for a movement of the microelectrodes of up to 5 mm in either direction making it
suitable for positioning microelectrodes in deep structures of a rodent brain.
The rest of the mechanism converts an oscillatory motion to a linear motion through a
ratchet-type configuration. Figure 3 illustrates the basic unit where there are two comb-
like arrays on either side. These generate the actual force. They are connected to a
cross piece that converts oscillatory motion in concert with a spring to a pulsatile linear
motion of the vertical shaft. This connects to some gears which do a mechanical
transformation.
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Figure 2. Functional MEMS Micromachines Attached
to Sensing Bioelectrodes. The gears have features as
small as 50 microns, less than the size of a period on a
printed page. (Courtesy of Dr. J. Muthuswamy,
Bioengineering Department, ASU)
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Figure 3. Schematic Diagram of a MEMS Motor
Complete With a Method of Converting
Oscillatory Motion to Linear Motion. (Courtesy of
Dr. J. Muthuswamy, Bioengineering Department, ASU)
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