When in 1990 IBM arranged 35 individual xenon atoms to spell out “IBM,” the feat heralded a new era of nanofabrication. And it was so totally cool. But there’s not much you can really do with xenon atoms, and the process had to be performed under a near vacuum at close to absolute zero. A new technique that is much more flexible was recently reported by a group in Munich.

The Munich team manipulated individual DNA molecules into position using an atomic force microscope as a cantilever. The process was performed at room temperature and in solution, making it relatively accessible to a wide range of labs. But the quantum leap forward achieved by using DNA is that it can be readily functionalized. For example, the Munich group attached both a fluorophore and a biotin group to their DNA. Furthermore, DNA can act as a template or “seed” for self assembly of larger structures, such as those demonstrated using DNA staples to create nanoscale shapes and patterns. The Munich team attached a piece of DNA to the microscope tip and picked up from a “depot” pieces of DNA with complementary stretches to the tip-bound DNA. The cantilever then moved the DNA to the assembly area. The assembly area had an anchored DNA molecule that also was partially complementary to the moved piece of DNA, so the moved piece could be immobilized at the destination. The tip-bound piece of DNA was re-used thousands of times without loss of fidelity.  I’ve actually oversimplified the binding/unbinding process a bit, and in actuality the group makes ingenious use of the orientation of hybridized DNA molecules to take advantage of either “shear” or “zipper” binding/unbinding geometries to aid their efforts. You can find more details about that in their Science article.

While it’s unlikely that you will be buying any mass-produced products manufactured with these new techniques, the ability for researchers to construct objects to exact specifications may greatly aid materials and life-science research.

Korean researchers report the development of a robot powered by heart muscle cells from a rat. The researchers coated a biocompatible polymer with heart cells that pulse in synchony in the presence of glucose, obviating the need for an external power supply. These beating cells permit the robot to move its six legs. The robot has three short front legs and three longer back legs, which are all attached to a central rectangular body. As the heart cells contract, the longer rear legs bend inwards. This creates a difference in friction between the front and rear legs, which pushes the robot forward. The scientists measured the robot’s average speed at about 100 micrometers per second (or about 2.2E-10 MPH). The lead designer, Sukho Park at Chonnam National University, Korea, says these crab-like robots could be used inside the body to clear blocked tubes or arteries.

This made me think of another really neat use for the heart muscle cells, which would be to make a glucose-powered electricity generator. The basic concept would be to coat a micro-balloon with the cells and use their contracting force to drive a nano-machined generator. The concept is shown below. The advantage would be that you could power small electronics or anything else that runs off electricity using only glucose. Although each single generator may not make much power, linking thousands of nano-generators together may generate usuable quantities of power.

Heart muscle cells coat a micro balloon and contract in synchrony. The expelled fluid drives a generator using nano-machined gears.
 

Here on Biotech Mashup we generally report on life-science related stuff. But sometimes, something so cool comes along that we just have to spread the word. This time it’s the Bradford Robotic Telescope, located on Mount Teide in Tenerife, the Canary Islands. What is so cool about this site is that they have a telescope that you can submit jobs to. So if you are interested in a particular piece of the sky, you can aim the telescope and have it take a picture for you. They have a 14-inch diameter telescope and the turn-around time is days to weeks. There is also an image gallery if you just want to see what other great pictures people took and then posted. It’s free to use, and you need to register to aim the camera. And if you think the origins of life might just be from outer space, then you might really have some fun here searching for hospitable galaxies.

As reported on LiveScience.com, researchers have for the first time “filmed” an electron in motion around a nucleus. Previously, indirect visualization methods were used that could only measure the effect of an electron’s movement, whereas the new technique can capture the entire event. Extremely short flashes of light are necessary to capture an electron in motion. A technology developed within the last few years can generate short pulses of intense laser light, called attosecond pulses, that can be used to visualize the electron motion. An attosecond is 10^-18 seconds, which can be put into perspective this way: one attosecond is related to a second as a second is related to the age of the universe, according to Johan Mauritsson of Lund University in Sweden. “It takes about 150 attoseconds for an electron to circle the nucleus of an atom,” he said. Using another laser, scientists can guide the motion of the electron to capture a collision between an electron and an atom on film. The length of the film Mauritsson and his colleagues made corresponds to a single oscillation of a wave of light. The results are detailed in the latest issue of the journal Physical Review Letters. A movie of the event is also on the LiveScience website.