Scientists Found a Way to Control Heat With Electricity - and It Could Cool the Chips Behind AI

Heat is the quiet enemy of modern electronics. Pack more transistors onto a chip and it runs hotter; the hotter it runs, the more speed and efficiency you lose. And yet, for all our precision in routing electricity, our main tools for dealing with heat are still remarkably blunt - heat sinks, fans, and thermal paste that simply let warmth spread out wherever it likes. We conduct electricity like a symphony. Heat, we mostly just mop up.

A team at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL), working with The Ohio State University and Amphenol Corporation, has now demonstrated something much closer to a switch for heat - a way to make thermal energy flow far more strongly in a chosen direction, on command, using nothing but an electric field.

1. A dial for heat

The result, published in the journal PRX Energy, is deceptively simple to state. The researchers took a special crystal and applied an electric field across it. Along the direction of that field, heat then travelled through the material nearly three times more efficiently than it did in the perpendicular directions.

What makes that remarkable is the scale of the effect. Physicists have nudged the thermal conductivity of bulk materials with electric fields before, but only by a few percent - typically about 5 to 10%. This jump of close to 300% is, by the team's accounting, somewhere between 30 and 60 times larger than anything previously documented in a bulk solid under an external electric field. It turns a marginal curiosity into a genuine control knob.

2. Why steering heat is so hard

In a solid, heat does not flow like a liquid. It travels as phonons - tiny, collective vibrations of the atoms in the crystal lattice, rippling through the material like sound. Anything that disrupts those vibrations - defects, disorder, competing motions - scatters the phonons and slows the flow of heat. Left alone, phonons scatter in all directions, which is why heat tends to spread out diffusely rather than run where we want it.

That is exactly the problem inside a dense chip: heat pools into hot spots and has no preferred path out. Being able to give it one - a low-resistance lane in a chosen direction - is a long-standing wish in thermal engineering.

3. Watching heat with neutron beams

To see why the field helped, the team turned to one of ORNL's specialties: inelastic neutron scattering, which lets researchers watch atomic vibrations directly. ORNL senior researcher Michael Manley led those measurements; the work also drew on Ohio State's expertise in thermal transport and on crystals grown and 'poled' (pre-aligned with a field) by Amphenol.

The neutrons revealed the mechanism. When the electric field aligned the material's polar regions, phonons whose atoms vibrate along the poling direction suddenly lasted much longer before scattering - their lifetimes stretched - while those vibrating across it did not. Longer-lived phonons carry heat farther, so the crystal conducts heat far better along the field than across it. In effect, the field builds a temporary highway for heat and points it in one direction.

“Being able to control both how fast and in what manner heat flows could lead to devices that manage thermal energy far more efficiently.”
- Puspa Upreti, ORNL, the study's first author

4. Why it matters: cooler AI, less wasted energy

The reason a heat dial is exciting is that so much of modern technology is thermally bottlenecked. A few directions this could open up:

The deeper shift is conceptual. For a century we have treated heat as something to be endured and dissipated. An electrically tunable, directional heat valve suggests we might one day design with heat - routing it as deliberately as we route current.

What we still don't know

• Lead. PMN-PT contains lead, which brings regulatory friction for consumer electronics. Translating the effect into a lead-free relaxor is an important next step.
• It is directional. The big gain is along the field axis; the material does not simply conduct heat better everywhere at once. That is the point - but it also shapes how it would be used.
• From bench to device. This is a clean laboratory demonstration in a single crystal. Building it into practical chips, coolers, or energy converters is engineering that still lies ahead.

Even with those caveats, the headline is a hopeful one: heat, long the passive villain of electronics, just became a little more like something we can command.

Sources

• Puspa Upreti, Delaram Rashadfar, Raffi Sahul, Douglas L. Abernathy, Joseph P. Heremans, Raphael P. Hermann, Michael E. Manley, ‘Electric Field Control of Phonon Lifetimes and Thermal Conductivity in Relaxor-Based Ferroelectric,’ PRX Energy vol. 5 (2026), DOI 10.1103/5d1z-wg4p
• Oak Ridge National Laboratory: Electric field tunes vibrations to ease heat transfer
• ScienceDaily: This electric field trick boosted heat flow by nearly 300% · SciTechDaily: Scientists Find a Way To Control Heat Flow With Electricity

Curated by Jerry Cards - jerrycards.com. We research the week's most consequential tech, science, and business news so you don't have to. More at jerrycards.com/news.