A Microcombustor Coupled with A Piezoelectric Unimorph for Power Generation

This article highlights the design of a unimorph for electric power generation and tested with two loading conditions. The unimorph comprises a piezoelectric ceramic bonded onto a steel disk, operating in d₃₁ radial mode so that lateral stresses cause a charge difference through the thickness of the unimorph. The experimental methods of testing were, firstly to apply a uniformly distributed pressure pulse to the underside of the disk using compressed air. Secondly to couple the unimorph to a 5 mm³ combustion chamber, and burning a stoichiometric mixture of H₂:O₂ metered at 5 ml/min. Testing has caused the unimorph to deflect by up to 50 mum and become stressed, in doing so generating electrical charge through the piezoelectric effect. Results have shown that milli-Watts of power can be generated with this configuration of piezoelectric unimorph.