The Internet of things (IoT) is undergoing an explosive growth. In the future, intelligence will be embedded into all things in our living environment. The sparsely spatial distribution of IoT devices has raised new issues for the power supply and power management technologies. The ambient energy harvesting and wireless power transfer are two most promising technologies for enabling the everlasting operation of the IoT devices. The METAL group has work on the kinetic energy harvesting technology during the last decade. New power conditioning solutions were proposed for enhancing the energy harvesting capably. We will continues devoting ourselves to the research on more reliable and efficient power solutions for the coming IoT era!

Representative publications:

New generation of energy harvesting circuits: J15, J13, C27, C24

Self-powered energy harvesting circuit designs: J9, C20

Applications: J14, C20

Wireless power transfer: J1

Circuit simulation is an essential tool for the efficient design of power and energy circuits and systems. Based on our proposed extended impedance method (EIM), we have successfully realized the efficient analyses and optimization of different power conversion systems, such as piezoelectric generator, class-E resonant converter, and flyback converter. We will continue working on this topic towards the development of an efficient frequency-domain simulation tool for the design and optimization of general power electronics.

Representative publications:

Class-E resonant inverter simulation and optimization: J8, J5, C26, C22, C16, C11

In the study of kinetic energy harvesting using piezoelectric materials, because of the mechatronic synergy in piezoelectric energy harvesting systems, the energy flow details as well as the dynamics of the electromechanical system should be rationally represented in a holistic point of view. We continuously work on this topic, in order to develop a joint dynamic model and analytical solution for the precise prediction of harvested power and dynamic analysis of practical piezoelectric devices.

Representative publications:

Electromechanical joint dynamics of energy harvering systems: J16, J10, J7, J4, J3, C28, C25, C18, C7

Additional dynamic concerns in real energy harvesting systems: J11, J6

It was shown that the piezoelectric power generation can be boosted by using the advanced switching power conditioning circuits. We work on different electronic and mechatronic self-powered solutions towards the implementation of the synchronized switch power boosting circuits in practical stand-alone energy harvesting systems. The obtained insights can be also applied in the optimization of other mechatronic or electromechanically coupled systems.

Representative publications:

Mechatronic designs for energy harvesting: J12, C15

Besides working on the power solutions on distributed IoT systems, we are also interested in the realization of human factored IoT. The applications range from smart sensing floor to other IoT solutions in smart energy, smart city, smart building, etc. The power solution and the function of the human factored IoT have very close relation. Our goal on distributed IoT devices is to make all IoT devices designed with human factors and energy self-sufficiency, such that to manifest humanity by advancing the ubiquitous IoT technology.

Representative publications:

Energy harvesting backpack: C29