PIEZOELECTRIC CANTILEVER DESIGN WITH BISTABILITY SYSTEM FOR KINETIC ENERGY HARVESTING FROM WALKING HUMAN ACTIVITY

• Main Author: Fauziah, Andyaningrum
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/44894
• Institution: Institut Teknologi Bandung

Nowadays, Handphone battery drain is a common problem experiencied by people everyday. The shortage of electricity sources and limited capacity of powerbank system for that problem need other solutions. The one that is potential to be the next energy resources is harvesting energy system. In this research, such a system is developed to harvest kinetic energy of walking human at 2 Hz. Sinusoidal vibration from walking human can be used to generate the vibration into electricity. Electricity that generated by piezoelectric with input from walking is not optimal since mismatch frequency between piezoelectric (110Hz) and walking activity. To optimize the harvested energy, piezoelectric can be integrated with mechanical – magnet coupling. The mechanical – magnet coupling through bistability can affect piezoelectric to vibrate outside its Eigen frequency. In this research, cantilever and magnet is used as mechanical-magnet coupling. Eigen frequencies of cantilever design with 52 variations are being predicted through analytical and numecical calculation. Design with reduced moment of inertia that is greater than mass loss proved to effectively lower Eigen frequency. Six complete configuration designs that have Eigen frequency nearest to 2 Hz then made as prototype. Two-level harvesting energy system has considered in this research. The measured harvesting energy systems are its free vibration while sinusoidal respons realized using walking simulator with six chosen designs of cantilever. The best results obtained are 6 second of time decay and 43,3 mJ of energy.