Auxetic Cantilever Beam Energy Harvester

This paper develops an auxetic cantilever beam energy harvester (ACBEH) to enhance the harvesting power from ambient vibration sources. A finite element analysis was performed to verify the power increase mechanism of the ACBEH. The simulation model of the ACBEH comprises of three main components: support, tip mass, and cantilever beam with a re-entrant hexagonal auxetic structure in which a piezoelectric element bonded to top of the auxetic region by using a thin elastic layer of epoxy. The performance of the ACBEH was computationally investigated and compared with an equivalent conventional energy harvester with a plain cantilever beam where they are attached to a bridge stay cable. The simulation result shows that the ACBEH excited by a harmonic acceleration of 1 m/s(2) at 3 Hz is able to produce electric power of 427.22 mu W, which is 2.51 times that of the power produced by the equivalent plain cantilever beam energy harvester (170.17 mu W). This paper opens up a great potential of using auxetic cantilever beam applications for different energy harvesting systems in Metamaterials, Acoustics, Civil, Electrical, Aerospace, Biomedical, and Mechanical Engineering.