1. DESIGN AND IMPLEMENTATION OF AN INTEGRATED FLOATING-GATE ELECTROSTATIC POWER MICRO-GENERATOR TRANSDUCERS 05, Seoul, Korea, June 5-9, 2005 Wei Ma, Libor Rufe, Yitshak Zohar and Man Wong Dept of Mech Engg., Dept of EE Engg., the Hong Kong University of Science and Technology ‘ Department of Aerospace and Mechanical Engineering, University of Arizona Speaker : C.M Lee Teacher : Cheng-Hsien Liu Date: 2007.5.9

2. 2007.5.9 2 Outline  Introduction  Generator design  Working principle  Testing  Conclusion

3. 2007.5.9 3 Introduction  Vibration-based micro generator electromagnetic, electrostatic, piezoelectric  Electrostatic is a good solution ease of integration with microelectronic devices  electrostatic generators mechanical resonator Electret( 永久帶電駐極體 )

4. 2007.5.9 4 Generator design  Standard CMOS floating-gate process Electret :floating-gate  Charged by electron tunneling, the floating gate works like one a non-volatile memory device Mechanical resonator: comb finger Power is generated when the capacitance change is induced by mechanical motion

5. 2007.5.9 5 Generator design mechanical resonator Electret

6. 2007.5.9 6 Working principle  Capacitance change  Mathematical model  Electrical model Kirchoff ’ s voltage

7. 2007.5.9 7  Taylor series expansion about a static equilibrium point Working principle

8. 2007.5.9 8 Working principle  Linear equivalent circuit

9. 2007.5.9 9 Testing

10. 2007.5.9 10 Testing

11. 2007.5.9 11 Conclusion  A single-wafer integrated floating-gate electrostatic power micro-generator was modeled, designed and fabricated  The measured power output agrees well with the modeling results, after properly accounting for parasite capacitance.