A laser tunable piezoelectric energy harvester

In this study, a tunable piezoelectric energy harvester manipulated by the light-activated shape memory polymer (LaSMP) is presented. A laminated cantilever beam consists of an elastic substrate, a light-activated shape memory polymer layer and piezoelectric patches is used as energy harvester. LaSMP layer could change its Young´s modulus under the exposure of UV lights and harvester´s natural frequency is regulated through the modulus change function of LaSMP. The tuned natural frequency of the harvester could match the external base excitation frequency and thus to achieve broadband resonance energy harvesting responses. For the first mode, the effective power increases from 1.18×10^-4μW to 1.3×10^-3μW when the natural frequency changes from 6.12Hz to 5.94Hz. For the second mode, the effective power increases from 0.003μW to 0.0304μW and for the third mode, it increases from 0.0086μW to 0.0879μW.