A real flux capacitor

Turns out there may really be (almost) such a thing as a flux capacitor. For those of you under 30 years of age, I digress to explain the term flux capacitor.

The term flux capacitor originated from the movie “Back to the Future.” In the original of the movie’s trilogy, Dr. Emmett "Doc" Brown builds a time machine based on a DeLorean DMC-1 car. The movie starred Michael J. Fox as Marty McFly and Christopher Lloyd as Emmett Brown.

Doc Brown’s time machine used a flux capacitor. While the movie never provides a precise definition of how the flux capacitor works, Doc said, its “what makes time travel possible” and required 1.21GW of electrical power to operate. In the movie, the flux capacitor appears as a box with three flashing lights forming a “Y” shape, and is mounted between the car’s two seats. When the DeLorean nears the point jumping through time, the lights flash at an ever faster rate.

For whatever reason, people have been using the term flux capacitor for years as a synonym of some technology that’s really cool — but doesn’t exist. However, perhaps Doc Brown was just ahead of this time.

In mid-August, a paper published in Nature Nanotechnology describes a new kind of capacitor. The device is constructed of concentric shells of graphene. Graphene is typically represented by a one-atom-thick flat sheet of sp2-bonded carbon atoms packed into a honeycomb crystal lattice. Think of it as an atomic-scale version of chicken wire made of carbon atoms and their bonds.

This new capacitor is created from “onion-like carbon” (OLC) formed into a series of concentric spheres of one-atom-thick sheets of carbon. Think of the capacitor as a series of balls of increasing size, each separated from the surrounding ones by a dielectric. According to the paper’s authors, the “onion-like” shells of graphene can produce discharge rates of up to 200V per second. This is “three orders of magnitude higher than conventional capacitors,” say the authors.

Compared with thin film lithium batteries, the OLC provides less energy per volume. However, the device provides more than 10,000 times more power per volume. The authors say the OLC may find applications that require large bursts of power, long lifetimes and decent storage capacity.

Doc Brown’s flux capacitor may finally be real.