When your winter jacket slows heat escaping your body or the cardboard sleeve on your coffee keeps heat from reaching your hand, you’re seeing insulation in action. In both cases, the idea is the same: keep heat from flowing where you don’t want it. But this physics principle isn’t limited to heat.
Electronics use it too, but with electricity. An electrical insulator stops current from flowing where it shouldn’t. That’s why power cords are wrapped in plastic. The plastic keeps electricity in the wire, not in your hand.
From coffee sleeves to wire coatings, insulators slow unwanted flow. In daily life, that’s heat flow. In electronics, it’s the flow of electricity.
Joe Christensen/iStock via Getty Images; Jose A. Bernat Bacete/Moment via Getty Images
Inside electronics, insulators do more than keep the user safe. They also help devices store charge in a controlled way. In that role, engineers often call them dielectrics. These insulating layers sit at the heart of capacitors and transistors. A capacitor is a charge-storing component – think of it as a tiny battery, albeit one that fills up and empties much faster than a battery. A transistor is a tiny electrical switch. It can turn current on or off, or control how much current flows.
Together, capacitors and transistors make modern electronics work. They help phones store information, and they help computers process it. They help today’s AI hardware move huge amounts of data at high speed.
What surprises most people is how thin these insulating, current-quelling dielectrics are. In modern microchips, key dielectric layers can be only a few nanometers thick. That’s tens of thousands of times thinner than a human hair. A modern phone can contain billions of transistors, so at that scale, slimming them down by even 1 nanometer can make a difference.
The key insulating layers in advanced electronics can be only a few nanometers thick – that’s thousands of times thinner than a human hair.
Mahest Nepal, Vladimir Zlotnik/iStock via Getty Images, Qualcomm
As an electrical and material scientist, I work with my adviser, Tara P. Dhakal, at Binghamton University to understand how to make these insulating layers as thin as possible while preserving their reliability.
Thinner dielectrics don’t just shrink devices. They can also help store more charge. But at such scale, electronics get finicky. Sometimes what looks like a breakthrough isn’t quite what it seems. That’s why our focus is not just making dielectrics thin. It’s making them both thin and trustworthy.
What makes one dielectric better than another?
In both capacitors and transistors, the basic structure is simple: They contain two conductors separated by a thin insulator. If you bring the conductors closer, more charge can build up. It’s like two strong magnets with a sheet between them – the thinner the sheet, the…
