A novel design of a map-tuning piezoelectric vibration energy harvester

Abstract

In this paper, a new design of a self-tuning bimorph PZT beam for maximum vibration energy harvesting is introduced. As is well known, a PZT beam harvester captures the most energy as it resonates with the ambient vibration. The ambient excitation frequency varies in nature so that proper tracking of the ambient frequency and adjusting the harvester’s resonance frequency accordingly would assure the most energy retrieved. The harvester introduced in the paper is composed of an elastic beam partially covered with two-sided PZT patches, the same as most others, but the method of tuning its resonance frequency is novel. A movable intermediate rigid support is attached to the beam and by adjusting the support’s position according to the sensed ambient frequency, the beam’s resonance frequency will coincide with the ambient frequency such that the harvested vibration energy is maximized. The theoretical analysis employs Hamilton’s principle, the assumed-mode method, and the receptance method. Numerical results are obtained and compared with the experimental ones. They show excellent agreement in a frequency versus support’s position chart. The most significant feature is that there can be up to ±35% of resonance frequency tunability. This achievement provides substantial advantages in power-harvesting applications. An experiment for base excitation to simulate the ambient vibration is setup as well and the results show that as little as 5% excitation frequency variation would cause more than 70% output voltage drop if there were no tuning ability. The novel design could significantly enhance the harvested energy in a short duration of time.

Tuning Techniques for Piezoelectric and Electromagnetic Vibration Energy Harvesters

“…Based [35][36][37][38] They tune the stiffness of a cantilever beam by changing the position of a clamp supporter placed along such a beam.…”

“…In [38], instead, a technique able to change the clamp support position during the operation of the harvester is presented and discussed with reference to a P-RVEH. The harvester introduced in this paper is composed by an elastic beam partially covered with two-sided piezoelectric patches.…”

“…As shown in Figure 20, a movable intermediate rigid support is attached to the beam. By adjusting the support's position (by means of a step motor that drives a linear guide and moves the support to an appropriate position) according to the sensed ambient frequency, the beam's resonance frequency is In [38], instead, a technique able to change the clamp support position during the operation of the harvester is presented and discussed with reference to a P-RVEH. The harvester introduced in this paper is composed by an elastic beam partially covered with two-sided piezoelectric patches.…”

“…In Figure 20. Schematic representation of the clamp position change based MTT proposed in [38]. A summary of the described clamp position change based MTTs is reported in Table 5.…”

The Design of a MRE-Based Nonlinear Broadband Energy Harvester

“…Zhou et al [6] introduced a 2 DOF (degree of freedom) vibration magnifier, the relay beam, to enhanced the vibration of the attached piezoelectric materials. Huang and Lin added a moving support to the traditional 1DOF energy harvester which made the effective length of the vibration beam is tunable and hence the tunable resonance frequency [7]. Soliman et al composed the micro-generator based on electromagnetic induction instead of piezoelectric and developed it by introducing a stiffness tuning stopper which broadens its resonance band [8].…”