A method for forming a unique, environmentally-friendly micron scale autonomous electrical power source is provided in a configuration that generates renewable energy for use in electronic systems, electronic devices and electronic system components. The configuration includes a first conductor with a facing surface conditioned to have a low work function, a second conductor with a facing surface having a comparatively higher work function, and a dielectric layer, not more than 200 nm thick, sandwiched between the respective facing surfaces of the first conductor and the second conductor. The autonomous electrical power source formed according to the disclosed method is configured to harvest minimal thermal energy from any source in an environment above absolute zero. An autonomous electrical power source component is also provided that includes a plurality of autonomous electrical power source constituent elements electrically connected to one another to increase a power output of the autonomous electrical power source.

A thermionic energy conversion system, preferably including one or more electron collectors, interfacial layers, encapsulation, and/or electron emitters. A method for manufacturing the thermionic energy conversion system. A method of operation for a thermionic energy conversion system, preferably including receiving power, emitting electrons, and receiving the emitted electrons, and optionally including convectively transferring heat.

A thermionic energy conversion system, preferably including one or more electron collectors, interfacial layers, encapsulation, and/or electron emitters. A method for manufacturing the thermionic energy conversion system. A method of operation for a thermionic energy conversion system, preferably including receiving power, emitting electrons, and receiving the emitted electrons, and optionally including convectively transferring heat.

Various disclosed embodiments include combined heating and power modules and combined heat and power devices. In an illustrative embodiment, a combined heat and power device includes a heating system including: at least one burner; at least one igniter configured to ignite the at least one burner; a fluid motivator assembly including an electrically powered prime mover; and a heat exchanger fluidly couplable to the fluid motivator assembly. At least one alkali metal thermal-to-electricity converter (AMTEC) has a high pressure zone and a low pressure zone, the high pressure zone being thermally couplable to the at least one burner, the low pressure zone being thermally couplable to the heat exchanger.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.

A small-gap device system, preferably including two or more electrodes and one or more spacers maintaining a gap between two or more of the electrodes. A spacer for a small-gap device system, preferably including a plurality of legs defining a mesh structure. A method of spacer and/or small-gap device fabrication, preferably including: defining lateral features, depositing spacer material, selectively removing spacer material, separating the spacer from a fabrication substrate, and/or assembling the small-gap device.