The present invention discloses an improvement for maintaining nanometer separation between electrodes in tunneling, thermal tunneling, diode, thermionic, thermoelectric, thermophotovoltaic, current limiting, resettable fusing, relays, circuit breakers and other devices the design of. At least one electrode has a curved shape, the curvature of which is changed by temperature. Some embodiments use nanoseparation to limit or stop the electrical current. Other embodiments reduce heat conduction between the two electrodes when compared to the prior art. The result is an electronic device that maintains two close parallel electrodes in a stable equilibrium with a nanogap between the two electrodes over a large area in a simple configuration for ease of manufacturability, and the resulting The devices described above are used to convert heat into electricity for cooling, or to limit or interrupt current flow.