The same overheating problem that happens to our laptops also plagues computer servers and data centers around the world—and heat management is only getting harder as computer chips get more compact and powerful.

Understanding how heat moves through chips at the microscale is essential for continuing to improve their performance. Unfortunately, most methods for measuring heat flow struggle with multilayered devices like the electronics that power our modern world.

Now MIT researchers have demonstrated a new way to study how heat moves through multilayered materials, combining X-rays that penetrate multiple layers with laser pulses to deliver heat. The researchers used the technique to measure how heat moves inside a promising device for transistors and flexible electronics.