An Extended-Range Vibration Energy Harvester Based on Internal Resonance

Results are presented for the design and testing of a vibration energy harvesting device that converts ambient mechanical vibration into electricity. The working principal of the device is based upon internal resonance-a nonlinear dynamic response in which vibration modes of a structure can couple when their natural frequency ratios occur as integer multiples. The resulting response enables the harvester to generate power over an extended frequency range in comparison to linear-dynamics-based harvesters when subject to harmonic external excitation. Measurements of displacement and power generated from a prototype demonstrate this behavior. The prototype is also shown to the generated maximum power under random base excitation when the ratio of the first two natural frequencies is closest to 2:1.