TY - JOUR
T1 - Scaling and characterisation of a 2-DoF velocity amplified electromagnetic vibration energy harvester
AU - O'Donoghue, D.
AU - Frizzell, R.
AU - Punch, J.
N1 - Publisher Copyright:
© 2018 IOP Publishing Ltd Printed in the UK.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Vibration energy harvesters (VEHs) offer an alternative to batteries for the autonomous operation of low-power electronics. Understanding the influence of scaling on VEHs is of great importance in the design of reduced scale harvesters. The nonlinear harvesters investigated here employ velocity amplification, a technique used to increase velocity through impacts, to improve the power output of multiple-degree-of-freedom VEHs, compared to linear resonators. Such harvesters, employing electromagnetic induction, are referred to as velocity amplified electromagnetic generators (VAEGs), with gains in power achieved by increasing the relative velocity between the magnet and coil in the transducer. The influence of scaling on a nonlinear 2-DoF VAEG is presented. Due to the increased complexity of VAEGs, compared to linear systems, linear scaling theory cannot be directly applied to VAEGs. Therefore, a detailed nonlinear scaling method is utilised. Experimental and numerical methods are employed. This nonlinear scaling method can be used for analysing the scaling behaviour of all nonlinear electromagnetic VEHs. It is demonstrated that the electromagnetic coupling coefficient degrades more rapidly with scale for systems with larger displacement amplitudes, meaning that systems operating at low frequencies will scale poorly compared to those operating at higher frequencies. The load power of the 2-DoF VAEG is predicted to scale as PL ∝ s5.51 (s = volume1/3), suggesting that achieving high power densities in a VAEG with low device volume is extremely challenging.
AB - Vibration energy harvesters (VEHs) offer an alternative to batteries for the autonomous operation of low-power electronics. Understanding the influence of scaling on VEHs is of great importance in the design of reduced scale harvesters. The nonlinear harvesters investigated here employ velocity amplification, a technique used to increase velocity through impacts, to improve the power output of multiple-degree-of-freedom VEHs, compared to linear resonators. Such harvesters, employing electromagnetic induction, are referred to as velocity amplified electromagnetic generators (VAEGs), with gains in power achieved by increasing the relative velocity between the magnet and coil in the transducer. The influence of scaling on a nonlinear 2-DoF VAEG is presented. Due to the increased complexity of VAEGs, compared to linear systems, linear scaling theory cannot be directly applied to VAEGs. Therefore, a detailed nonlinear scaling method is utilised. Experimental and numerical methods are employed. This nonlinear scaling method can be used for analysing the scaling behaviour of all nonlinear electromagnetic VEHs. It is demonstrated that the electromagnetic coupling coefficient degrades more rapidly with scale for systems with larger displacement amplitudes, meaning that systems operating at low frequencies will scale poorly compared to those operating at higher frequencies. The load power of the 2-DoF VAEG is predicted to scale as PL ∝ s5.51 (s = volume1/3), suggesting that achieving high power densities in a VAEG with low device volume is extremely challenging.
KW - 2-degree-of-freedom
KW - electromagnetic generator
KW - energy harvesting
KW - scaling analysis
KW - velocity amplification
KW - vibration energy harvesting
UR - http://www.scopus.com/inward/record.url?scp=85049689712&partnerID=8YFLogxK
U2 - 10.1088/1361-665X/aac297
DO - 10.1088/1361-665X/aac297
M3 - Article
AN - SCOPUS:85049689712
SN - 0964-1726
VL - 27
JO - Smart Materials and Structures
JF - Smart Materials and Structures
IS - 7
M1 - 075019
ER -