The efficiency of energy generation depends not only to the amplitude of input displacement but also excitation frequencies.
The optimal input displacement range is discovered to be in between 8 to15mm under excitation frequency of 4Hz. However, this
excitation frequency is not favourable due to its availability. It is achieved only when someone is in running mode and this
frequency is the system threshold. The operational input frequency is, therefore, set to be lower than 4Hz in order to increase the
life span of the system.