In an article posted online at Ars Technica, author Chris Lee discusses new advances in nuclear magnetic resonance spectroscopy (NMR) that may have untold possibilities.

NMR, as Chris writes, is "the gold standard in spectroscopy. To put it in perspective, the discovery and subsequent technical developments in (NMR) spectroscopy—including the magnetic resonance imaging used in hospitals—have garnered four Nobel prizes, the last being in 2002. Every hospital, chemistry, and biochemistry lab worthy of the name has at least one of these things."

As powerful as the technology is, it has limitations when working with small samples. First of all, the signal from the atomic nucleus is proportional to the sample size - so small samples simply do not produce large enough signals to detect accurately. A second problem is related to the magnetic field. NMR data is interpreted by looking at how the resonance frequency changes. Generally this is accomplished by using large magnetic coils, that produce a homogenous field near their center - where the spectroscopy is performed. The smaller the sample size, the smaller the coil required. The smaller the coil, the more difficult it is to obtain a homogenous field - and subsequently, accurate readings.

To combat this problem, Jacob Bart and co-workers from the MESA+ Research Institute for Nanotechnology, created a strip of metal on a printed circuit board with a metallic ground plate beneath. "The geometry of the strip-line and ground plane produce a nicely confined and homogenous magnetic field." To boost the magnetic field strength, "they made a center portion of the strip line very narrow. This had the effect of vastly increasing the current density and, consequently, the magnetic field strength. This intense magnetic field is located very close to the wire, but is still quite homogenous."

Using this setup, Bart and colleagues were able to perform NMR on samples as small as 100nl - previously thought to be much too small for accurate detections.

Read more from the September 25th article.