Microelectromechanical Systems (MEMS) Based-Ultrasonic Electrostatic Actuators on a Flexible Substrate

• Published in: IEEE electron device letters Vol. 33; no. 7; pp. 1072 - 1074
• Main Authors: Sangpyeong Kim, Xu Zhang, Daugherty, R., Lee, Ed, Kunnen, G., Allee, D. R., Forsythe, E., Junseok Chae
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2012; Institute of Electrical and Electronics Engineers
• Subjects: Acoustics; Actuators; Applied sciences; Arrays; Circuit properties; Computer science; control theory; systems; Control theory. Systems; Design. Technologies. Operation analysis. Testing; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Electrostatic actuator; Exact sciences and technology; Integrated circuits; Micro- and nanoelectromechanical devices (mems/nems); microelectromechanical systems (MEMS); Micromechanical devices; Oscillators, resonators, synthetizers; Robotics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Substrates; ultrasonic actuator; Voltage-controlled oscillators; Sound pressure level; Polyethylene; Suspended structure; microelectromechanical systems (MEMS); Voltage controlled oscillator; Capacitive transducer; Xylene polymer; Acoustic wave; Driver; Buffer system; Micromachine; Electrostatic actuator; Flexible structure; Output voltage; Integrated circuit; ultrasonic actuator; Diaphragm; Ultrasound; Electrostatic actuators; Microelectromechanical device
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2012.2195630

We present a microelectromechanical systems (MEMS)-based electrostatic actuator on a flexible substrate, made of polyethylene naphthalate, which emits acoustic waves at ultrasonic frequencies. The actuator has a suspended diaphragm, made of parylene, of 2-6-mm diameter and a 6-μm gap between the diaphragm and substrate. The actuator is driven by hydrogenated amorphous silicon integrated circuits. The driving circuits consist of voltage-controlled oscillator and buffer chain, which can tune the output voltage from 3 to 32 V with 35-V supply. A single actuator emits ultrasonic waves at 25 kHz and pressure of 27-dB sound pressure level (SPL), and a 1 × 2 array emits up to 34.6-dB SPL at 1-cm distance.