Project TitleProximity Sensor Based on Bi-Stable Nano-Cantilever
Track Code2004-054
Short Description

A novel feedback controlled bi-stable nano-cantilever as logic switches and sensing device.



A novel nano-electromechanical system (NEMS) is developed at Northwestern, which has bi-stable states to enable the proximity sensing/probing, on/off logic switch and other various applications. Due to the interesting structural characteristic and nano-scale feature size, NEMS is promising for superior electronic components and sensors. Northwestern's NEMS bi-stable device is based on a nano-cantilever using carbon nanotube (CNT) or silicon nanowire (NW) material structure. With voltage applied, it can achieve the two equilibrium positions for functions (the pull-in and the pull-out configurations). This NEMS device is applicable to a wide range of applications including gap sensing devices, scanning probe microscope, ultrasonic wave detector, logic devices, nano-scale switches, random-access memory elements, electron counters, and bio-sensors.

Figure Nano-cantilever Bi-stable NEMS device and experimental validation. (a): Schematic of a two-terminal CNT based nano-cantilever device with feedback control. (b): Theoretical illustration of two equilibrium positions under applied voltage. (c-e): Experimental demonstration of nano-cantilever bi-stable probe. 

TagsNANOTECHNOLOGY: fabrication, SENSOR: biosensor, MATERIALS: electronic, instrumentation: microscopy
Posted DateDec 5, 2014 4:22 PM


Horacio D Espinosa* 
Changhong Ke 
Nicolaie A Moldovan 


• NEMS switch, random access memory elements and logic nano-devices 
• Scanning probe microscope, gap sensor and ultrasonic wave detection 
• Bio-sensor


• Nano-scale structure size 
• Feedback controlled 
• Easy integration to current microelectronics technology 
• Wide applicability


IP Status

Issued US patent No. 7,612,424

Marketing Contact

Arjan Quist, PhD 
Invention Asssociate 
(p) 847-467-0305 



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