Nanotechnology hasn’t panned out the way some investors thought. But one company, ZettaCore, is soldiering on with a technique for using nanotech to create memory chips with ultra-tiny storage cells that can be packed densely. The company said Sunday that it raised $21 million in a third round of funding.

If the Englewood, Colo.-based company succeeds in shrinking storage down to a microscopic scale, then society as a whole could look forward to all sorts of advances in portable electronics, which could store far more data than they can today.

ZettaCore is working with molecule-size materials — multi-porphyrin nanostructures — where each molecule can serve as a capacitor, which stores an electrical charge. While conventional memory chips become more flaky the more you shrink them, these structures remain stable even though they’re just a few nanometers, or 100,000 times smaller than a human hair, in length. ZettaCore believes it can make memory chips with the technology.

New investors include Globis Capital Partners, Itochu Technology Ventures, Yasuda Enterprise Development, Epic Ventures, and Panasonic Ventures. Existing investors are Draper Fisher Jurvetson, Kleiner Perkins Caufield & Byers, Radius Ventures, Oxford Biosciences, Access Ventures, Garrett Capital, and Stanford University. Panasonic Ventures said it expects ZettaCore’s technology to eventually be integrated into Panasonic’s products.

ZettaCore said it will use the new funds to expand overseas, start commercial production, and create new products. The first use of the technology is to make copper wiring adhere better to printed circuit boards, allowing for much thinner wires and more densely packed boards.

The company is headed by Subodh Toprani, a former Rambus executive. It was founded in 2001 by a trio of university scientists: chemists Werner Kuhr, David Bocian and Jonathan Lindsey.