Single atom scale (via Catalan Institute of Technology)
Carbon nano-tubes have some flexibility when it comes to its uses. You can find them incorporated in everything from carbon-fiber baseball bats to solar cells. In fact, I wouldn’t be surprised to find them made into some kind of new breakfast cereal (frosted nano-tube O’s?) at some point in the future. All kidding aside, these nano-tubes have yet again found their way into new technology, and this time it’s a weighty issue.
Scientists from the Catalan Institute of Technology (CIT) in Barcelona, Spain have used them to make a scale that can measure the weight of a single atom. That is what the team is saying to promote their project. However, the scale is even better than they are saying. Professor Adrian Bachtold and his team from CIT have designed a nano-mechanical sensor capable of measuring the mass of one proton or 1.7 yoctograms (SI unit of mass that equals 1.7 X 10-24 g). The team made the sensor using a 150 nanometer long carbon nano-tube that traverses a trench or gap of the same length. The nano-tube ‘string’ vibrates at a frequency of around 2 GHz and changes when mass is introduced to the tube, thereby enabling the team to calculate mass. In order to take an accurate reading, the group needed to place the delicate sensor in an electrical-noise free vacuum environment with ultra-low temperatures to keep ‘stray’ atoms from interfering in the measuring process.
A series of successful tests were conducted in which one test showed the changes in mass when xenon atoms were introduced to the nano-tube string. While atom placement on the string was sporadic, the team hopes to design a string that is capable of capturing atoms on a specific area in the future which would give an even more accurate reading.