Writing very, very small

Note added, 12/5/2005: Dr. Cedric Loiret-Bernal has pointed out to me that Bioforce Nanosciences has not licensed "dip-pen nanolithography" from Northwestern. Not only does Northwestern hold the patent, but the term "dip-pen nanolithography" is trademarked. Therefore, it cannot be said that Bioforce is commercializing this technology. Instead, Bioforce is commercializing a very similar technology (over which there may be patent disputes in the future).

Dr. Loiret Bernal has also suggested some other more literary editing of my post. In a Wikipedia sort of collaborative spirit, I have incorporated his suggestions below in brackets to indicate Loiret-Bernal's authorship.


“Dip-pen nanolithography [DPN]” is a very high tech sounding term, but the concept is very simple. Essentially, it involves writing with a very tiny fountain pen. The pen, in this case, is an atomic force microscope tip mounted on a cantilever. The ink can include any sort of small molecule, and some fairly large ones, like buckyballs, DNA oligonucleotides, or proteins.

DPN came out of the lab of Chad Mirkin, at Northwestern and is being commercialized by his company, Chicago-based NanoInk, as well as another midwestern company, Bioforce Nanosciences. At the NanoCommerce conference in Chicago, I was privileged to interview Dr. Cedric Loiret-Bernal, CEO of NanoInk. That interview is now available on Nanotechnology.com’s multimedia page.

When first it appeared, DPN seemed like a solution in search of a problem. We were told that it could be used for drawing very tiny electronic circuits, but standard lithography does this very well, and is already coming close to the resolution of DPN, about 15 nm. Another use was the creation of array-type bioassays. However, Affymetrix has effectively tied up the intellectual property for oligonucleotide assays used for [DNA] gene expression. Besides which, all of the genes in the human genome can be assayed on a single microarray chip. Why then is a nanoarray necessary? Bioforce, particularly, is pitching the use of DPN for protein assays. However, nanoscale arrays are not really appropriate for proteins, since a single protein can have a diameter in the 10s of nanometers. DPN, IMHO, is overkill.

NanoInk, on the other hand, is pushing two very commercial uses for DPN.
1) Photomask repair
2) Coding [Encrypting] pharmaceuticals to fight counterfeiting [and illegal diversion].

Photomasks are used in the creation of semiconductor chips. It is very costly to discard photomasks that have a defect since a single such photomask may be worth as much as $250,000, given the time and equipment used to create it. DPN excels at the deposition of very small amounts of material at precise locations, controlled at the nanometer level, and so could be used to repair photomasks. NanoInk is already working [with] a manufacturer to commercialize this technology.

According to Loiret-Bernal, pharmaceutical companies lose about $25 billion in revenues due to counterfeiting every year, not to mention the potential product liabilities, if a drug doesn’t do what is supposed to do, or has side-effects it is not supposed to have. A case in point came up just recently; China is having trouble fighting the bird flu, because much of the vaccine it is using to vaccinate chickens and ducks turned out to be useless stuff churned out by counterfeiters. "While the rate of counterfeiting in the US is difficult to estimate, on a global scale, counterfeiting is a widespread problem and affects both developing and developed countries. The World Health Organization (WHO) has reported that up to 25% of medicines consumed in poor countries are counterfeit or substandard,” said Dr. Randall W. Lutter, Acting FDA Associate Commissioner for Policy &Planning, in testimony before Congress.

In general, the counterfeiters are not small operators, but other drug companies based in Asia or Africa, with sophisticated equipment. It is virtually impossible to distinguish their wares from the real thing without doing a full chemical analysis.

Nano to the rescue. NanoInk is already working with one pharmaceutical company to use DPN to put a code [an encryption] on each individual capsule or tablet that will tell when, where and by whom it was made. Eventually, Loiret-Bernal hopes to have six centers worldwide where the codes could be read from any suspicious batch of pills.