Significant power enhancement of magneto-mechano-electric generators by magnetic flux concentration

A magneto-mechano-electric (MME) generator comprising a magnetoelectric (ME) composite and magnetic flux concentrator (MFC) can effectively harvest the tiny magnetic noise to power the autonomous internet of things (IoT) sensor networks.

Passive Magnetic-Flux-Concentrator Based Electromagnetic Targeting System for Endobronchoscopy

In this paper, we demonstrate an innovative electromagnetic targeting system utilizing a passive magnetic-flux-concentrator for tracking endobronchoscope used in the diagnosis process of lung cancer tumors/lesions. The system consists of a magnetic-flux emitting coil, a magnetic-flux receiving electromagnets-array, and high permeability silicon-steel sheets rolled as a collar (as the passive magnetic-flux-concentrator) fixed in a guide sheath of an endobronchoscope. The emitting coil is used to produce AC magnetic-flux, which is consequently received by the receiving electromagnets-array. Due to the electromagnetic-induction, a voltage is induced in the receiving electromagnets-array. When the endobronchoscope’s guide sheath (with the silicon-steel collar) travels between the emitting coil and the receiving electromagnets-arrays, the magnetic flux is concentrated by the silicon-steel collar and thereby the induced voltage is changed. Through analyzing the voltage–pattern change, the location of the silicon–steel collar with the guide sheath is targeted. For testing, a bronchial-tree model for training medical doctors and operators is used to test our system. According to experimental results, the system is successfully verified to be able to target the endobronchoscope in the bronchial-tree model. The targeting errors on the x-, y- and z-axes are 9 mm, 10 mm, and 5 mm, respectively.

Double-Gap Magnetic Flux Concentrator Design for High-Sensitivity Magnetic Tunnel Junction Sensors

To improve the sensitivity of the magnetic tunnel junction(MTJ)sensor, a novel architecture for a double-gap magnetic flux concentrator (MFC) was studied theoretically and experimentally in this paper. The three-dimensional finite element model of magnetic flux was established to optimize the magnetic field amplification factor, with different gaps. The simulation results indicate that the sensitivity of an MTJ sensor with a double-gap MFC can be significantly better than that of a sensor with a traditional single-gap MFC, due to the fact that the magnetic magnification sharply increases with the decrease in effective gap width. Besides this, the half-bridge MTJ sensors with the double-gap MFC were fabricated using photolithography, ion milling, evaporation, and electroplating processes. Experimental results show that the sensitivity of the MTJ sensor increased by ten times compared to the sensor without the double-gap MFC, which underlines the theoretical predictions. Furthermore, there is no significant increase in the sensor noise. The work in this paper contributes to the development of high-performance MTJ sensors.

An Electromagnetic Targeting System With Semi-Circular Configuration for Navigating Endo-Bronchoscope

In this paper, we present an electromagnetic targeting system with semi-circular configuration for navigating endo-bronchoscope. This system consists of a magnetic-flux emitting electromagnets-arrays fixed on a semi-circular mechanical-support, magnetic-flux receiving electromagnets, and a magnetic-flux concentrator (i.e., silicon-steel collar) which fixed on distal end of a guide sheath of the endo-bronchoscope. In initial state, when the emitting electromagnets produce magnetic flux in sequence, the receiving electromagnets receive the magnetic flux and consequently produce voltage outputs by the electromagnetic induction. When the silicon-steel collar with the guide sheath travels through the system, the magnetic flux is concentrated by the collar. Thus, the voltage outputs of the receiving electromagnets are changed. By analyzing the change of voltage outputs, the location of the silicon-steel collar with the guide sheath is obtained/targeted. This means that the location of the endo-bronchoscope is also targeted.