Blog @ NanoVic - Nanotechnology Blog

The line between artificial and biological life is becoming increasingly blurry,and the latest development is robots that feed themselves. It’s not a new concept to create robots which don’t need ‘refueling’ so to speak, of course you can whack a few solar cells on to create a renewable fuel source. But the Bristol Robotics Laboratory has actually created the worlds first robot that eats unrefined biological material to produce it’s energy.

So what does a robot eat when it’s hungry? EcoBotII eats flies, generating electricity from a microbial fuel cell which digests the chitin in the exoskeleton of the insects. And although the power output is tiny, EcoBotII won’t break any speed records at a measly 13 cm per hour, it is able to be fuelled for 2 weeks on just 8 flies! At this stage EcoBotII has been ‘fed’ flies, but next generation EcoBotIII will not only attract it’s own food with a trap system using attractant pheremones, it will be the first complete artificial digestive system, able to excrete it’s own waste.

Why make a robot that can eat insects? One group that has been very interested, says scientist Allan Winfield, is organic farmers, who would be able to control pests without using pesticides, with the added bonus that the robots are able to ‘poo’ out nutrient rich fertiliser!

Just as we’ve all (hopefully) finally made the switch to energy-saving fluorescent light bulbs, researchers at the University of Glasgow have announced a way of utilising LEDs for household lighting.

LEDs are currently used in computers and mobile phones and are significantly more energy efficient, but because of the way they are designed they trap a lot of light, and have not been bright enough for household lighting uses. However, by creating microscopic holes in the surface of LEDs, more light can escape resulting in a brighter light for no more energy consumption. But the process is costly and inefficient.

Researchers at the University of Glasgow have used nanoimprint lithography to create the holes, which can be done on billions of LEDs for much lower cost. LEDs also last far longer than even current energy-efficient fluorescent bulbs.

Researchers at Cornell University have built a nanoguitar about the size of a red blood cell, and can play it too! 

The minute guitar is made of silicon crystal, carved out using a technique called electron-beam lithography. It can be played, not in the traditional way by plucking the strings, but through using targeted laser-light to hit the strings, which causes them to oscillate, creating interference patterns in the light reflected back which can be detected electronically and converted to audible notes. 

The nanoguitar demonstrates the possibility of manufacturing tiny mechanical devices using techniques originally designed for building microelectronic circuits, and its playing ability shows how such devices could substitute for electronic circuit components to make circuits smaller, cheaper and more energy-efficient. 

The technology may also be able to be used for the detection of contamination, with researchers finding they can detect the presence of a single bacterium attached to one such nanostructure via a change in its vibration.

To hear the guitar played click here.

Try to imagine the best way to power nanoscale electronics; for consistency and practicality, a nanoscale battery would be ideal.  To that end, scientists at Harvard University have developed the first self-contained nanoscale solar cell, in the form of a coaxial silicon nanowire.  Constructed from concentric layers of crystalline silicon doped with boron or phosphorus, the nanowire has an approximate diametre of 200 nm.  When struck by sunlight, electrons and positively-charged molecular ‘holes’ move inversely between the layers of the nanowire, creating enough current to power an electric circuit.  While still quite inefficient (the nanowire converts only 3% of sunlight into power, whereas conventional solar cells operate at 20-25% efficiency), the development is exciting in that offers an entirely new geometry for photovoltaic cells.  Improved efficiency should eventually see the nanowire offering reliable and harvestable energy for nanoelectronics.  I wonder if a nanoscale solar battery for my laptop is out of the question…..?  

Remember the 1980s song Video Killed the Radio Star? Hold that thought…a new nano application suggests that radio shouldn’t quite yet be regaled to yesteryear. Peter Burke and Chris Rutherglen of the University of California have constructed a wireless radio detector from carbon nanotubes. The newly developed nano ‘demodulator’ was successfully used to transmit classical AM music wirelessly from an iPod to a speaker several feet away. The music transmitted was audibly indistinguishable from that reaching the human ear directly. This marks the first time that a nano-sized detector has been demonstrated in an actual working radio system, and offers great hope for the eventual construction of a wireless communication system constructed entirely at the nano-scale. Burke and Rutherglen claim their work to be a functioning example of nanotechnology as opposed to nanoscience. The full report has been published by a journal of the American Chemical Society, Nano Letters.

I’m often asked: “Is there nano in the iPod nano, or is it just a marketing ploy?”. I’ve been confident in myself that the circuitry, the memory, and the screen all contained nanostructured materials, but I’d privately wondered if these were important – did they make the device as distinctive and powerful as it is?

The latest issue of Nature has provided the answer. In an article about “The physics prize inside the iPod”, Geoff Brumfiel explains that the key effect is giant magnetoresistance (GMR). The effect has been heralded as one of the first major applications of the fields of nanotechnology and ’spintronics’, opening up a way to build much smaller magnetic heads. Basically the heads consist of multiple layers of magnetic and non-magnetic materials only tens of nanometres thick. When all the layers were aligned in the same direction, electrons with the same alignment passed through the material easily, whereas those with the opposite alignment struggled. But when the layers were organized in an alternating ‘up-down’ alignment, all electrons encountered resistance. The net effect was a rise in resistance that was much bigger than any seen before. This led to devices that are very sensitive to tiny magnetic fields.

I’m delighted. The iPod is one of the most exciting developments of the last decade, and we can now confidently claim it in the nano family!

The unique manner in which Gecko’s can stick themselves to surfaces is often discussed in relation to nanotechnology, with the mechanism being a function of Casimir Forces arising from quantum-mechanical effects.  Scientists in the UK are now using the same principle but in reverse, which can cause objects to levitate rather than stick together!  Professor Ulf Leonhardt and Dr Thomas Philbin from St Andrews University say that by reversing the effects of Casimir Forces, friction between objects can be significantly reduced or eliminated, thereby enabling micro- and nano-machinery to run more smoothly. This could potentially improve the performance of everyday objects such as car airbags, computer chips and even those medical devices using lab-on-a-chip technology.  Unfortunately, due to the small scale of the quantum forces, this effect is currently only seen at the micro- and nano-scale.  I’m still holding out for the time when human levitation is on the horizon!

RoboCup is an international joint project which promotes AI, robotics, and related fields. It attempts to foster AI and intelligent robotics research by providing a standard problem where a wide range of technologies can be integrated and examined. RoboCup chose to use the soccer game as a central topic of research, aiming at innovations to be applied for socially significant problems and industries. 

As reported recently in the Brisbane Times, RoboCup 2007 was held at Georgia Tech.  Included in this year’s schedule was an event titled “Nanogram Soccer”.  Sponsored by the National Institute of Standards and Technology (NIST), the organizers hoped to show the potential for building tiny devices that could be used in manufacturing, biotechnology and other industries. They also hoped to develop manufacturing standards for the untapped field.

Five teams from the U.S., Canada and Switzerland built microscopic robots that competed in two events: a two-millimeter dash and a challenging slalom, where the robot must reach a goal that is blocked by stationary defenders that look like running men but are about the diameter of two hairs.  The events took place in a glass-enclosed cube and two high-powered microscopes projected the action onto a big screen.

I just wonder if their skills and abilities are equal to those of David Beckham - I guess it could be very hard to tell!

Planet82, a Korean company, has created an SMPD image sensor which can operate using a very small amount of light. This sensor will enable photos to be taken in near darkness eliminating the need to use a flash. According to Planet 82, nanotechnology is applied during sensor development enabling them to minimize sensor size and also increase unit pixels integrated in a limited area, which produces higher density as well as lower power consumption.

I am sure for even the amateur photographer, like myself, not having to rely on a flash would be beneficial. There are always times when you try to take a photo and the camera is unable to do so as it is too dark, even when using a flash.

Typically, progress in computational speeds is made by shrinking the logic-performing transistors used by computer chips. It is believed that chipmakers won’t be able to do this for much longer (only until around 2021 according to Intel). Without resigning themselves to one potential solution – simply building bigger chips – researchers at Hewlett-Packard have developed a way improving the chip circuitry by reworking the wiring with nanowires. HP hopes to make a prototype chip within a year. The new technology could extend the life of current chipmaking technologies and at the same time allow for manufacture of new chips that could outperform existing technology by a factor of three.