Effectiveness of Energy Transfer versus Mixing Entropy in Coupled Mechanical–Electrical Oscillators

Electrostatic energy harvesters convert kinetic into electrical via variable capacitors. Efforts to improve their power output are hampered by a lack of understanding the fundamental limit for conversion efficiency. In heat engines, theoretical efficiency is intrinsically related entropy and second law thermodynamics. Laying foundation similar concepts may be necessary establishing limit. Thus, mixing concept borrowed from statistical mechanics adapted here, first time, characterize transfer between coupled mechanical–electrical oscillators. The investigated system composed spring-mass an inductance-capacitor circuit capacitor. Combining two subsystems (electrical mechanical) generates entropy, referred as entropy. A non-dimensional study governing equations systems terms carried out. Trends in compared with trends total system, assuming conservative weak coupling mechanical domains, identical natural frequency It found that can predict peak effectiveness domains. For cases studied, maximum values occur when ratio domain 67%. independent initial conditions depends on squared nominal capacitor system.