Abstract
It is crucial to maintain constant temperatures in an energy-efficient way. Here we establish a temperature-trapping theory for asymmetric phase-transition materials with thermally responsive thermal conductivities. Then we theoretically introduce and experimentally demonstrate a concept of an energy-free thermostat within ambient temperature gradients. The thermostat is capable of self-maintaining a desired constant temperature without the need of consuming energy even though the environmental temperature gradient varies in a large range. As a model application of the concept, we design and show a different type of thermal cloak that has a constant temperature inside its central region in spite of the changing ambient temperature gradient, which is in sharp contrast to all the existing thermal cloaks. This work has relevance to energy-saving heat preservation, and it provides guidance both for manipulating heat flow without energy consumption and for designing new metamaterials with temperature-responsive or field-responsive parameters in many disciplines such as thermotics, optics, electromagnetics, acoustics, mechanics, electrics, and magnetism.
- Received 31 March 2016
DOI:https://doi.org/10.1103/PhysRevLett.117.055501
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Focus
A Thermostat that Consumes No Energy
Published 29 July 2016
Experiments show that a region next to changing hot and cold areas can be maintained at a fixed temperature without consuming energy.
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