A single material can now be programmed to force heat to flow backward from a cold area to a hot one.
Heat naturally spreads from hot to cold until everything reaches the same temperature. This experiment uses a thermoinductive effect to temporarily reverse that flow within a specific material. By controlling electrical currents, the system creates a thermal version of an inductor that stores and releases heat in cycles. This allows for localized cooling and heating that defies the standard intuitive path of thermal energy. Such a device could lead to a new generation of micro-electronics that manage their own temperature with extreme precision. It essentially gives us a transistor for heat, allowing for thermal circuits that were previously thought impossible.
Reverse heat flow with Peltier-induced thermoinductive effect
arXiv · 2605.05597
The concept of "thermal inductance" expands the options of thermal circuit design. However, the inductive component is the only missing components in thermal circuits, unlike their electromagnetic counterparts. Herein, we report an electrically controllable reverse heat flow, in which heat flows from a low-temperature side to a high-temperature side locally and temporarily in a single material by imposing thermal inertia and an ac current. This effect can be regarded as an equivalent of the "the