Last week was a busy one for Harris & Harris (NASDAQ:TINY), a publicly traded venture capital firm specializing in nanotechnology.

On Friday, the Motley Fool Rule Breakers recommendation announced it had invested $4 million as the lead investor in Xradia, a company that designs and manufacturers a suite of ultra-high resolution 3-D X-ray microscopes and fluorescence imaging systems which have applications in everything from semiconductors and advanced materials to biotechnology and nanotechnology.

Time will tell if the investment pays off, especially since it is a highly competitive field. But the fact Xradia is already working with Argonne National Laboratory to study interactions at the nanoscale is a promising start.

What was more promising, however, were recent announcements from two of the companies Harris & Harris has invested in.

First, Nanosys announced that DoCoMo Capital, a subsidiary of NTT DoCoMo (NYSE:DCM) -- which is itself a subsidiary of Nippon Telegraph and Telephone (NYSE:NTT) -- had entered into an agreement to develop one of Nanosys' nanotechnology platforms for potential opportunities in the wireless communications market. That's particularly noteworthy because DoCoMo Capital apparently thinks enough of the technology to fund its development and take an equity stake in the company.

The second bit of good news came compliments of Molecular Imprints, which says it has shipped one of its new step-and-flash imprint lithography pieces of equipment to a "leading semiconductor memory manufacturer."

Now there is nothing inherently special about the shipment of a piece of equipment, but it is an indication that the semiconductor industry is looking seriously at Molecular Imprint's equipment to help design and build next-generation semiconductor components at and below the 32-nanometer range.

I have long felt that one of the keys to success for start-up nanotech companies is their ability to enter into agreements and/or establish partnerships with leading corporations. Nanosys, which already has an agreement with Intel (NASDAQ:INTC), is doing this with DoCoMo Capital; Molecular Imprints, which sold some of its equipment to Hewlett-Packard (NYSE:HPQ) and Motorola (NSYE: MOT), is also doing the same with the semiconductor industry.

In and of itself, neither of these items guarantees Harris & Harris' success, but it sure beats the alternative of no new news and no partnerships. This is also just one of the many reasons why I continue to believe the company represents one of the better ways to invest in nanotechnology.

I encourage investors to watch for news of Xradia supplying its equipment to leading biotechnology or semiconductor companies. If it happens, it will be further proof that Harris & Harris is getting down to business in a way that should reap dividends for its investors.

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Fool contributor Jack Uldrich is the author of two books on nanotechnology, including Investing in Nanotechnology: Think Small, Win Big. He owns stock in Harris & Harris and Intel. The Fool has a strict disclosure policy.