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

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

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

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

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

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)

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:

Example 14: silicon Condenser Microphone Process Hijab and Muller, Digest of tech. Papers, Transducers 85, (1995), pp. 178 - 181

SEM photograph of the cross-section of the condenser microphone Hijab and Muller, Digest of tech. Papers, Transducers 85, (1995), pp. 178 - 181

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

(ii) Piezoresistive

(iii) Capacitive

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

(ii) Piezoelectric Cantilever-Based

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)

(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)

(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)

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)

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)