A generator with nonlinear spring oscillator to provide vibrations of multi-frequency

Piezoelectric MEMS Energy Harvester for Low-Frequency Vibrations With Wideband Operation Range and Steadily Increased Output Power

(2011) Huicong Liu et al.   JOURNAL OF MICROELECTROMECHANICAL SYSTEMS

A low profile vibro-impacting energy harvester with symmetrical stops

(2010) Scott Moss et al.   APPLIED PHYSICS LETTERS

A piezoelectric bistable plate for nonlinear broadband energy harvesting

(2010) A. F. Arrieta et al.   APPLIED PHYSICS LETTERS

Wideband vibration energy harvester with high permeability magnetic material

(2009) X. Xing et al.   APPLIED PHYSICS LETTERS

Electromagnetic energy harvesting from vibrations of multiple frequencies

(2009) Bin Yang et al.   JOURNAL OF MICROMECHANICS AND MICROENGINEERING

A MEMS-based piezoelectric power generator array for vibration energy harvesting

(2008) Jing-Quan Liu et al.   MICROELECTRONICS JOURNAL

A vibration energy harvesting device with bidirectional resonance frequency tunability

(2008) Vinod R Challa et al.   Smart Materials and Structures