Frequency Splitting and Transmission Characteristics of MCR-WPT System Considering Non-Linearities of Compensation Capacitors

The frequency splitting phenomenon and transmission characteristics have been research hotspots in the field of magnetically coupled resonance wireless power transfer (MCR-WPT). In this paper, non-linear dynamics theory was innovatively introduced into the research, and non-linear coupled transmission dynamics modelling of the MCR-WPT system was established considering the non-linearities of the compensation capacitor. The mechanism of the frequency splitting phenomenon of the MCR-WPT system was revealed through systematic mathematical analyses based on the modelling. The analysis results showed that the system usually has dual natural frequencies which are low resonance frequency and high resonance frequency. Based on non-linear dynamics theory, the transmission characteristics of the system with different non-linear parameters were discussed comprehensively in relation to the modelling. The results of the numerical simulations and theoretical analyses showed that non-linear parameters can cause the jumping phenomena with the output responses, and the output responses in the vicinities of the lower resonance frequencies were extremely sensitive to changes in the coupling coefficient. According to analyses of the linear and non-linear systems, the energy transmissions performed in the vicinity of the high resonance frequency had a wider working frequency band and a better transmission stability under non-linear conditions.

High Frequency FM MEMS Accelerometer Using Piezoresistive Resonators

A novel frequency modulated (FM) accelerometer based on piezoresistive resonators is presented. The accelerometer uses two differential resonators, connected to the accelerometer proofmass by an amplifying leverage mechanism. The piezoresistive double-mass resonators are electrostatically driven in anti-phase and the output signal is measured piezoresistively by applying a bias current to the connecting microbeam of the double-mass resonators. Accelerometers were fabricated using SOI technology with a 5 µm device layer. Fabricated resonators show a high resonance frequency around 705 kHz and a Q-factor close to 20,000 when measured in vacuum. Preliminary measurements show a sensitivity around 0.46 Hz/g for a single resonator.

Design and Simulation of High SNR Varying Thickness Embedded Strain Sensing Polymer Microcantilever for Biosensing Applications

To convert induced surface stress of a bio-functionalized microcantilever into an electrical signal; U shaped piezoresistive detection technique is mostly preferred over other techniques due to its several advantages. But the inherent disadvantage of this technique is thermal stress sensitivity as a source of noise which reduces its signal to noise ratio [SNR]. Polymer microcantilever has larger stress sensitivity due to its low youngs modulus of elasticity. Varying thickness cantilever satisfy this desired criteria as compared to other configurations of cantilever and has high resonance frequency. Taking all these aspects into consideration, the objectives of proposed study is to design and simulate multilayer varying thickness microcantilever. The numerical analysis is performed using CoventorWare a commercial MEMS design and FEM Multiphysics tool. It is observed that the SNR of the varying thickness microcantilevers design is improved by more than 70%, over normal rectangular design.