What we sense in the Newtonian world is vastly different from the experience of individual molecules, where slight thermal and quantum changes may have profound impact. The challenge is to harness the features and functions these nano-physical properties offer to attain new, technological ends.
Working at the atomic level enables the exploitation of properties that have yet to be harnessed except within naturally occurring biological systems. Harvard's George Whitesides argues that such organic systems are, in fact, nano-machines.
One start-up taking advantage of this is EngeneOS. The Boston-based company designs and manipulates proteins to build everything from programmable biomolecular devices to nano-antennas. Nano-antennas, for example, uniquely marry inorganic nano-crystals with organic materials (engineered bio-molecules), creating antennas for RF signals to control molecules in living cells or even control the delivery of drugs to patients.
Another promising area that takes advantage of quantum effects is the use of quantum dots. Quantum dots, ranging in size from a few nanometers to 1 micron, are small metal or semiconductor "boxes" that contain and confine electrons. One possible application is the use of quantum dots for high-intensity light emitters. The release of these emitters in an all-optical switch application could achieve switching times faster than 15 terabits per second.
Exploiting properties of the nano-scale world enables new opportunities, but it also presents limits and challenges.
One of the biggest challenges today is the "interface" problem--scaling up a world of atoms and electrons for use in the human-scale world. Companies are still experimenting with how to deal with the challenge, developing processes that don't require human manipulation, such as self-assembly, or trying to build products that may be "hybrid."
Hybrid products may use existing processes, like CMOS (complementary metal-oxide semiconductor), but work with novel materials and architectures to capture some advantages from nano-scale physical properties. This has been particularly true for early work to replace DRAM and is important now for the creation of novel forms of computer memory, such as nonvolatile RAM.
Nantero, a Draper Fisher Jurvetson-backed company, is developing a carbon nano-tube-based technology for building this universal, nonvolatile memory, which takes advantage of van der Waals forces to create the basic on-off junctions of a bit. Van der Waals forces are interactions between atoms that enable non-covalent binding. They rely on electron attractions that arise only at the nano-scale level as a force to be reckoned with. The company is using this property in its design to integrate nano-scale material properties with established CMOS fabrication techniques.
Another challenge is the lack of tools for researchers and companies as they manipulate and build in the world of the small. In the technology industry, we take for granted the extensive tools available to information technologists to aid them in their work. Few tools exist for work at the atomic scale.
In fact, work at the atomic level became possible only through the relatively recent invention of the scanning tunneling microscope and more recently atomic force microscopy. EngeneOS, for example, is developing its own biomolecular CAD system to aid in the design of its devices. Tools like that must proliferate throughout the industry to enable nano-scale assembly of structures and features to be fully exploited.
As start-ups and others take advantage of biological systems, quantum physics and chemistry to innovate, we will see new designs and new architectures emerging. Molecular motors will emerge to carry out everything from molecular assembly and DNA sorting to logic queries for molecular computers. While the laws of physics limit our Newtonian world, quantum effects, new materials and biological nano-machines may break through those limits, with the potential to drive much of the innovation in technology over the next 20 years.
DFJ has an equity investment in Nantero.