Personnel

FICs - Prof. Philip K. T. Mok

Description

Energy reuse and energy recycling has become an important factor to reduce global warming. The idea of using ambient energy to power up small electronic devices has been attracting a lot of attention in recent years. These energy-autonomous devices self-power themselves over a full lifetime by harvesting the energy coming from the surrounding environment. These devices are particular useful in some unique applications such as wireless remote field sensors which require continuous monitoring of objects in storage or in transit, implantable biomedical devices in which recharging of the batteries needs costly and risky surgery, rescuing devices which determine the locations of disaster survivors in the wilderness. There are basically four main ambient energy sources: solar energy, vibration energy, thermal energy and electromagnetic energy. These energy sources always fluctuate in nature and the power supplied by these energy harvesters also fluctuates and is of low power in nature. Therefore, a power converter is essential to regulate and manage the harvested energy. Current power management circuits consist of several analog building blocks such voltage reference, error amplifier, etc. consume quite a significant amount of power. This power consumption may be higher than the power obtained from the energy harvesting system. As a result, the energy harvesting system will not be able to sustain its own function except under strong ambient energy sources condition such as bright sunlight, extreme temperature difference or strong vibration. In order to have these energy-autonomous devices to be truly self-powered in all conditions, a low-power power management circuit must be developed. The objective of this proposal is to develop an ultra-low-power power management integrated circuit for energy-autonomous electronic device application. This includes the development of new control methods and new circuit topologies of the controller design with ultra-low-power performance. A new series of ultra-low-power analog circuits will also be developed for this application. The focus will be on how to minimize the power management IC such that the energy harvesting system can acquire energy efficiently in all ambient conditions. Other issues related to how to convert the energy from the harvester to a higher voltage for storage and how to control and deliver the energy to the energy-autonomous devices, etc. will also be explored in this project.

Source: RGC | ITF