Blogs

Controlling the movement of microscopic particles is tough; controlling the movement of thousands of tiny particles is a challenge indeed. Chemical and biological screening are two applications that would benefit from a technique which involves the manipulation of large numbers of droplets contained in a small quantity of fluid, and researchers in the US and Austria have recently demonstrated that they can steer those tiny droplets within an electrically insulating fluid using light¹.

The ingenious chaps over at Apple Inc. have come up with a bright idea that may one day save you the inconvenience of lugging around chargers and spare batteries for your portable media players and mobile phones.

Mankind once again makes its mark on the red planet, this time with the arrival of NASA's Phoenix lander. It successfully touched down yesterday in Mars's northern polar region and is reportedly in good health. The scientific mission will soon begin analysing the geology and climate of Mars, with particular emphasis on learning more about the history of water on the planet. One of its science packages is the meteorological station provided by the Canadian Space Agency (CSA), which includes a laser measurement device known as LIDAR that will be used to study atmospheric processes for the first time on another planet.

Organic semiconductors have made their way into many applications in recent years, including computer displays, lighting and solar panels. They have several advantages over their conventional electronic counterparts, including low cost and comparatively simple manufacture. Their optical and electrical properties make them suitable for transistors and light emitting diodes, but it has not been possible to develop electrically-driven laser diodes with them. Researchers at Imperial College, London, have been working with a class of material that may well make such devices a reality.

A biometric identification technique you may be seeing more of in the coming years is vein scanning. The veins inside a person's hand, or just one of their fingertips, are imaged and the results passed through a software algorithm to obtain a unique identifier for that person. In an identification scenario, that person would then be authorised or denied access, depending on whether their identifier matched one in the database and for which access was granted.

Researchers at Stanford and the University of California at Santa Barbara have demonstrated an optical logic gate on a semiconductor chip, possibly leading the way towards a practical device for use in quantum computing.

This may seem a little off-topic, but nature often abounds with solutions to problems we have yet to dream of and, since nature often has a smarter way of doing things, developed through the trials and errors of evolution, we can learn a lot from the living world around us. It turns out, for example, that the mantis shrimp has evolved powerful vision that includes the ability to detect polarised light, and not just linearly polarised light; they can also sense circular polarisation.

Laser eye surgery is already a commonplace procedure, most particularly in the field of corrective vision, and now lasers have found a new application in ophthalmology as a treatment for eye cancer.

The "solution looking for a problem", as it was called at the time of its invention, is now 48 years old. On the 16th of May 1960, Theodore Maiman used a high power flashlamp to optically pump a ruby rod, either end of which was partially coated with silver, to produce the world's first working laser.

Lasers in space had a more ominous meaning back in the Reagan era, but hopefully that tarnished image of our optically coherent friend is behind us. Communication has now been demonstrated between two satellites separated by a distance of 5000 km, using lasers no larger than a matchbox and weighing only 130 g.