Durga P. Kar

Wireless energizing system for an automated implantable sensor.

The wireless drive of an automated implantable electronic sensor has been explored for health monitoring applications. The proposed system comprises of an automated biomedical sensing system which is energized through resonant inductive coupling. The implantable sensor unit is able to monitor the body temperature parameter and sends back the corresponding telemetry data wirelessly to the data recoding unit. It has been observed that the wireless power delivery system is capable of energizing the automated biomedical implantable electronic sensor placed over a distance of 3 cm from the power transmitter with an energy transfer efficiency of 26% at the operating resonant frequency of 562 kHz. This proposed method ensures real-time monitoring of different human body temperatures around the clock. The monitored temperature data have been compared with a calibrated temperature measurement system to ascertain the accuracy of the proposed system. The investigated technique can also be useful for monitoring other body parameters such as blood pressure, bladder pressure, and physiological signals of the patient in vivo using various implantable sensors.

Bi-directional magnetic resonance based wireless power transfer for electronic devices

In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84% in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency.

Droplets merging through wireless ultrasonic actuation

A new technique of droplets merging through wireless ultrasonic actuation has been proposed and experimentally investigated in this work. The proposed method is based on the principle of resonant inductive coupling and piezoelectric resonance. When a mechanical vibration is excited in a piezoelectric plate, the ultrasonic vibration transmitted to the droplets placed on its surface and induces merging. It has been observed that the merging rate of water droplets depends on the operating frequency, mechanical vibration of piezoelectric plate, separation distance between the droplets, and volume of droplets. The investigated technique of droplets merging through piezoelectric actuation is quite useful for microfluidics, chemical and biomedical engineering applications.

Study of Resonance-Based Wireless Electric Vehicle Charging System in Close Proximity to Metallic Objects

A typical magnetic resonance coupling based wireless Electric Vehicle (EV) charging system consists of a transmitting coil at the charging station and a receiving coil in the vehicle. In order to maintain good energy transfer e-ciency of the wireless charging system, the efiect of the proximal metallic object in the vicinity of the receiving coil has been investigated. Both from the simulation and experimental measurement, it has been observed that the resonance based wireless energy transfer system is very sensitive to the nearby metallic objects, leading to signiflcant deterioration in energy transfer e-ciency. This efiect on the energy transfer e-ciency is also seen to be difierent for difierent physical spacing between the transmitting and receiving coils. It is also found that the operating resonant frequency for optimum energy transfer e-ciency changes with the metallic object in close proximity to the receiving coil. The simulated results well agree with the experimental results. The analysis will provide future guidelines for designing an e-cient resonance coupling based wireless charging system for EVs even in the presence of metallic objects.

Wireless energizing of piezoelectric component using ultrasonic wave

A new technique of wireless energy transfer to piezoelectric component using ultrasonic wave has been investigated. Finite element simulation has been carried out in order to analyze the operating mechanism of the proposed ultrasonic energy transfer system. It is observed that the piezoelectric receiver gets excited when it captures the generated ultrasonic waves from another piezoelectric transmitter. It is found that maximum excitation occurs in the receiver at the mechanical resonant frequency of the piezoelectric component. The vibration displacement of the receiver depends on the operating frequency, ultrasonic energy and distance between the transmitter and receiver piezoelectric components. The simulated field pattern ensures the feasibility of wireless energy transmission through ultrasonic wave.

Energy transfer to piezoelectric component through magnetic resonant coupling

In this paper, a non-contact energy transfer method has been experimentally investigated to drive a piezoelectric component operating in the thickness vibration mode. The energy transfer system uses a receiving coil connected to the piezoelectric component placed away from an energy-transmitting coil along its central axis. The impedance characteristics and frequency characteristics of the voltage developed across the piezoelectric component operating in the thickness vibration mode are experimentally investigated. It is observed that a mechanical resonance vibration is excited in the driven piezoelectric component through strongly coupled magnetic resonance between the coils as well as due to the mechanical resonance of the piezoelectric component. It has been found that the voltage developed across the piezoelectric component is maximum at its resonance frequency. It is also found that the energy received by the piezoelectric component connected to the receiving coil depends on the operating frequency, coil design, and distance between the coils.