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In this paper a novel electrostatic MEMS combined shock sensor and normally-closed switch is presented. The switch uses combined attractive and repulsive forcing to toggle a cantilever beam to and from the pulled-in position. The attractive force is generated through a parallel plate electrode configuration and induces pull-in. The repulsive force is generated through electrostatic levitation from a third electrode and serves to pull the beam out of its pulled-in position. A triboelectric transducer converts impact energy to electrical energy to provide voltage for the third electrode, which temporarily opens the switch if enough impact energy is supplied. Triboelectricity addresses the high voltage requirement for electrostatic levitation. The multi-electrode sensor also addresses the low current output from the generator because it acts as an open circuit between the parallel plate and levitation electrodes. A theoretical model of the switch is derived to analyze stability and the dynamic response of the cantilever. Threshold voltages to pull-in and release the beam through repulsive forcing is calculated. Output voltage plots from a prototype generator under a single impact are applied to the sensor-switch model to demonstrate the working principle of the sensor-switch is feasible.
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Contact resonance atomic force microscopy using long elastic tips
Abstract In this work, a new theoretical model for contact resonance atomic force microscopy, which incorporates the elastic dynamics of a long sensing tip is presented. The model is based on the Euler–Bernoulli beam theory and includes coupling effects from the two-beam structure, also known as an ‘L-shaped’ beam in the literature. Here, high-accuracy prediction of the sample stiffness, using several vibration modes with a relative error smaller than 10% for practical working ranges, is demonstrated. A discussion on the model’s capability to predict the dynamic phenomena of eigenmode veering and crossing, as the force applied to the sample increases, is presented. The L-shaped beam model presented here is also applicable for structural applications such as: micro-electro-mechanical systems, energy harvesting, and unmanned aerial vehicle landing gear.
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- Award ID(s):
- 1934772
- PAR ID:
- 10476480
- Publisher / Repository:
- IOP
- Date Published:
- Journal Name:
- Nanotechnology
- Volume:
- 35
- Issue:
- 7
- ISSN:
- 0957-4484
- Page Range / eLocation ID:
- 075503
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1088/1361-6528/ad0bd2
