Question

Provide a short description, for each of the subject, of no more than a paragraph and one representative figure.

a) Working principles of micro-sensors (chemical, optical, acoustic wave, pressure and thermal)

b) Working principles of micro-actuators (thermal forces, shape-memory alloys, piezoelectric and electrostatic)

c) Materials selection for micro-sensors/actuators (e.g., substrates and wafers, silicon compounds such as dioxide, carbide, nitride, and polycrystalline, silicon piezoelectric, gallium arsenide, piezoelectric crystals, polymers and films)

d) Micro-sensors/actuators fabrication processes (e.g., photolithography, oxidation, chemical vapor deposition, chemical and plasma etching, bulk micromanufacturing, surface micromanufacturing and LIGA process)

Answer 1

Working principle of micro sensors: These sensors work on the principle of interactions between the biomolecules in the sample and the analyte (usually in solution) in the sensor. Signal transduction is the changing of the physical properties of the sensingmaterials after specific type of chemical reactions.

Working principle of micro actuators:

Material selection for micro sensors:

The suitability of a microsensor for a particularapp ca on s essen a y e erm ne y scharacteristic performance.Different applications require different sensorperformance.

Microsensors for resonant application

Microsensors for microcantilever sensors

Below specific requirements

selection for micro actuators:

fabrication process:

The fabrication of microsensors includes three major steps: (1) synthesis of the porous metal or metal oxide nanostructures using a sacrificial template, (2) deposition of the electrodes onto alumina substrates, and (3) alignment of the nanostructures between the electrodes. The invention has been demonstrated for methane detection at room temperature (using tin oxide, with carbon nanotubes as the sacrificial template). The microsensor offers low power consumption (no heating required), compact size, extremely low cost, and simple batch-fabrication.