1. Example 12: Micronozzles
Process Flow
Cap etched Si nozzle mold
Farooqui and Evans, JMEMS 1, 86 (1992)

2. Process Flow (ctd.) Silicon nitride nozzle with molds still in place
Farooqui and Evans, JMEMS 1, 86 (1992)

3. Process Flow (cntd.) Nozzle with submicron aperture
Nozzle with 150 nm aperture
Farooqui and Evans, JMEMS 1, 86 (1992)

4. Example 13: Linear-Motion Microactuator
Perspective view
Expansion/contraction and net displacement
Robins etal., JMM 1, 247 (1991)

5. Process
Robins etal., JMM 1, 247 (1991)

6. Analysis The model parameters are given as: and
N is the number of bars per actuator half section, and L, w, and t are the actuator’s dimensions. Eps is Young’s modulus of poly-Si.
Robins etal., JMM 1, 247 (1991)

7. Analysis (cntd.) The effective force is given by:
d13 is the piezoelectric constant of PZT, Epz is its Young’s modulus, and V is the applied voltage.
The overall displacement is:

8. Example 14: silicon Condenser Microphone
Process
Hijab and Muller, Digest of tech. Papers, Transducers 85, (1995), pp

9. SEM photograph of the cross-section of the condenser microphone
Hijab and Muller, Digest of tech. Papers, Transducers 85, (1995), pp

10. Example 15: Different Types of Pressure Sensors
(i) Piezoelectric

11. (ii) Piezoresistive

12. (iii) Capacitive

13. Example 17: Different Types of Microactuators
(i) Diaphragm-Based

14. (ii) Piezoelectric Cantilever-Based

15. Example 17: Overhanging Microgripper
(I) Design
The poly-Si microgripper is 2.5 mm thick and 400 mm long.
It consists of a closure driver and two drive arms which connect to extension arms that extend to the gripper jaw.
The beam widths for the drive arms and comb teeth are 2 mm, but that for the closure drive is 10 mm to provide relative rigidity.
When voltage is applied between the closure driver and drive arms, the drive arms tend to close the gripper jaws. Note that the drive arms are at the same potential which avoids current flowing between the gripper jaws when they are fully closed
Kim etal., IEEE Solid State sensor and Actuator Workshop (1990)

16. (II) Force Analysis
The size of the force depends upon the initial jaw displacement and on the voltage applied to close it against the specimen; for example, if each gripper jaw needs to close 2 mm to be in contact with the specimen, then 23 V applied between the driver (stator) and the drive arms initially brings the jaws in contact with the object. Voltages higher than 23 V will generate a gripping force.
Kim etal., IEEE Solid State sensor and Actuator Workshop (1990)

17. (III) Process Flow Boron diffusion.
Deposition of phosphosilicate glass (PSG); deposition and definition of poly-Si; removal of poly-Si on wafer backside.
Deposition of thick PSG; annealing; front-to-back alignment-window etching.
Definition of PSG break lines on front-side; definition of Si die and V-groove on backside; etching EDP.
Final (times) PSG etching.
Kim etal., IEEE Solid State sensor and Actuator Workshop (1990)

18. Fabrication is complete but the die not yet removed from water.
Three conducting lines crossing the end of the support cantilever in the gripper arms.
Flexible comb-drive structures, extension arms, and gripper jaws.
Kim etal., IEEE Solid State sensor and Actuator Workshop (1990)

19. Photograph of the packaged gripper
SEM picture of a one-celled protozoa being held by the gripper; the object is 40 mm long and 7 mm in diameter.
Kim etal., IEEE Solid State sensor and Actuator Workshop (1990)