An energy harvesting device is a new way to supply power to micro electronic devices when a conventional energy sources does not exist by converting the mechanical energy into electrical energy. The mechanical energy that have been chosen is vibration from human activities where it can be easily harvested from human foot. Piezoelectric energy harvester has been fabricated and installed in a street shoe to convert the vibration to electrical energy. The piezoelectric material that have been selected is Polyvinylidene Fluoride Polymer Film (PVDF) because of the flexibility and the durability of the material among the others materials. Most of the previous researchers focus on harvesting vibration energy on heel. However, there are other parts of foot that can generate higher energy than the heel. Therefore, the purpose of this study is to find out the part of foot that can harvest the highest energy and investigate the human activities that can generate high electric energy. The parts of foot are heel, ball of foot and thumb toe and the human activities are walking at speeds of 2 km/h, 3 km/h and 4 km/h, and running at speeds of 5 km/h, 7 km/h and 9 km/h. From the results obtained, the location of the harvester that produced optimum peak-to-peak voltage (Vpp) is at the ball of foot with 1.9 V at 9 km/h speed. The higher the speed and stress, the higher the electrical energy that the energy harvester can produce

Microalgae have been considered as a reliable feedstock for biodiesel production and regarded as the promising alternative source to replace petroleum-based fuels. Production of biofuel derived from microalgae undergoes several processes, including cultivation, harvesting, extraction and biofuel conversion.However,recovery of intracellular content is time-consuming and difficult process as the biodegradability of microalgae is strictly hindered by the rigid nature of the cell wall. Hence, pretreatment of microalgae becomes an inevitable process to facilitate cell wall disruption and liberation of organiccell contents for the biofuel production.This paper aims to review and compare the various pretreatment methods(mechanical and non-mechanical)of microalgae with respect of their strength and limitation