Tham khảo tài liệu 'the mems handbook mems applications (2nd ed) - m. gad el hak episode 1 part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 3-32 MEMS Applications TABLE Device dimensions and measurement results from Park and Gianchandani 2003 which are in terms of gauge pressure. C0 is the capacitance at zero gauge pressure. Linearity for DEV 1 was measured over 0-250 kPa. For DEV2 DEV3 and DEV4 linearities were measured over 0-100 kPa. Reprinted with Permission from Park . and Gianchandani . 2003 A Servo-Controlled Capacitive Pressure Sensor Using a Capped-Cylinder Structure Microfabricated by a Three-Mask Process IEEE ASME Journal of Microelectromechanical Systems 12 2 pp. 209-220. DEVICE DEV1 DEV2 DEV3 DEV4 Segmented Skirt T1 T3 gm 12 12 12 T2 gm 18 18 20 20 H G1 gm 10 15 15 15 R1 gm 500 500 500 500 R2 gm 1000 1000 1000 1000 Bonding Temperature C 550 550 450 450 Unpackaged Open Loop C pF Sensitivity -408 -154 -124 -136 ppm kPa Sensitivity fF kPa Linearity Closed Loop Sensivity V kPa Linearity 20kPa Packaged Open Loop C0 pF Sensitivity -137 -164 ppm kPa ac ap fF kPa Linearity Closed Loop Sensitivity V kPa Linearity 20kPa For the predictive modeling of this device finite element analysis is preferred because the simultaneous flexing of the diaphragm skirt electrode and sidewall are not easily expressed in closed-form analytical manner. In general it is necessary to use coupled-field analysis to model this device because both pressure and electrostatic forces must be simulated. Experimentally a number of devices with 2 mm overall diameter but varying in other dimensions were fabricated and alternative design in which skirt electrode was divided into segments to relieve residualstress provided 10 -20 more open-loop sensitivity for similar overall dimensions. The device dimensions and performance results are summarized in Table . In addition Figures and respectively provide examples of the open-loop and .
