MEMS-Based Thermionic Energy Converter for AC Power Output

Engineers in Prof. Roger Howe’s laboratory have designed a thermionic microelectromechanical systems (MEMS) energy converter that can be used to generate AC electric power directly from high temperature heat. This invention utilizes a model of thermionic current that depends on the gap between the microcathode and an underlying anode. The variation in current can be harnessed to produce AC power without the cost and complexity of the external inverter which is needed to convert DC to AC power in conventional thermionic system. By eliminating the inverter this technology simplifies the integration of thermionic converters (which are attractive for applications such as topping cycles in concentrated solar power plants) into the energy grid. This technology could also be used for natural gas-fired micro-cogeneration applications. Applications: 1) Solar thermal energy - AC electricity production directly compatible with power grid 2) Natural gas electricity production - thermionic conversion for small-scale combined heat and power (e.g. water heaters)