The Latest Scientific Inventions and Cool New Research

There is always something new happening in the world of science. In fact, there are so many new scientific discoveries and inventions, that it’s virtually impossible to stay abreast of all the new information. Here are a few really cool new inventions that are under development.

Using flying beetles for search and rescue

New research, funded by the Defense Advanced Research Projects Agency (DARPA), has demonstrated how flying beetles could one day be used surveillance purposes or for search-and-rescue and similar missions.

Michel Maharbiz is trying to take advantage of the beetle's natural abilities by melding insect and machine. The team has wirelessly controlled a giant flower beetle with implanted electrodes and a radio receiver on its back. With a nearby computer they can send wireless signals to the beetle including commands to take off, hover in place, turn left, and turn right and land.



Oscillating electrical pulses delivered to the beetle's optic lobes trigger takeoff, while a single short pulse ceases flight. Sending electrical signals to the left or right basilar flight muscles make the animal turn right or left, respectively.

The reason behind the selection of the giant flower beetle is that it is large and can carry a heavy payload. It would need to carry a camera and heat sensor for search-and-rescue missions for example.

Artificial gecko feet using carbon nanotubes

Scientists have been trying to duplicate the adhesiveness of gecko feet for years without success. Liming Dai, a professor at the University of Dayton, and Zhong Wang, director of the Center for Nanostructure Characterization at Georgia tech, have developed a new adhesive that closely mimics the structures on gecko feet.

Gecko feet are covered with millions of micro-scale hairs which branch into even smaller hairs. The hairs each have a weak electrical interaction with a surface, and add up to a strong force over the area of the foot.

The researches came up with an adhesive made of carbon nanotubes whose structure closely resembles that of gecko feet. The material is 10 times more adhesive than the geckos' feet and it’s easy to lift back up.

Dai’s group, using a silicon substrate, grew arrays of vertically aligned carbon nanotubes topped with an unaligned layer of nanotubes, like rows of trees with branching tops. The adhesive force of these nanotube arrays is very strong, about 100 newtons per square centimeter. That’s enough for a .15 inch x .15 inch square to support a 3 pound weight. The adhesive properties stayed the same when tested on surfaces, including glass plates, polymer films, and rough sandpaper.

One problem with these materials is that when the material gets dirty they don’t work well. No one has been able to do that. Dai says that carbon nanotubes' versatility may help overcome the dirt problem. Dai is developing adhesive nanotube arrays that have the nanotubes coated with proteins that change their shape in response to temperature changes. The idea is that robot feet could heat up when they get clogged, sloughing off the dirt so that it can keep walking.

Self-cleaning clothing

Researchers at Monash University, in Victoria, Australia, led by organic chemist and nanomaterials researcher Walid Daoud, have discovered a way to coat fibers with titanium dioxide nanocrystals, which break down food and dirt in sunlight. They have coated natural fibers such as wool, silk, and hemp so that they will automatically shed food, grime, and even red-wine stains when exposed to sunlight.

Titanium dioxide is used in sunscreens, toothpaste, and paint, and it is a strong photo catalyst. In the presence of water vapor and ultraviolet light, it forms hydroxyl radicals, or decompose organic matter. However, says Daoud, "these nanocrystals cannot decompose wool and are harmless to skin." The nanocrystal coating doesn’t change the look or feel of the material.

Titanium dioxide also destroys bacteria in the presence of sunlight by breaking down the cell walls of the microorganisms. Self-cleaning fabrics would be useful in hospitals and other medical settings.

The material stands up to red-wine stains, which are very difficult to remove. After 20 hours of exposure to simulated sunlight, titanium-dioxide-coated wool shows almost no sign of the red stain, while the untreated wool remains boldly stained. Other stains disappear faster: coffee stains fade away in two hours, while blue-ink stains disappear in seventeen hours.

Materials that use nanoparticles have been developed in the past. Stain-repellant fabrics and paints that are currently on the market typically have a nanoparticle or nanofiber coating that causes drops of liquid to roll off instead of getting absorbed into the material, taking small particles of dirt and grime with them.

The sunlight requirement has not stopped the technology from getting commercial interest. Several wool manufacturers have suggested that they'd like to evaluate the technology, Daoud says.

What is Nanoelectronic?

Nanoelectronic is concerned with understanding and exploiting the properties of devices, which have dimensions at the nanometre scale.

Microelectronics will gradually evolve into nano-electronic. In fact, this has already happened as can be seen from the smallest feature size of present integrated circuits, which is below of one micrometer. It is currently believed that optical lithography can be used for ground rules down to 150 nm and might even be used for the 100 nm generation and below. This would imply an increasing process and mask complexity, and consequently, increasing the cost.

Molecular-scale electronic has been widely touted as "the next step" in electronic miniaturization, with theory and research suggesting that single molecules may have the capability to take the place of today's much larger electronic components.

Therefore, what are the advantages of scaling down of devices?

Speed of operation - Reduction of the parasitic capacitances associated with non-conductive paths in an electronic device leads to a higher cut-off frequency. This enables a device to operate at much higher speeds. Density - An obvious advantage. This reduces size and cuts materials cost. Power dissipation - This is reduced due to lesser resistance in interconnects and currents flowing in smaller circuits. In lasers, the use of lower dimensional systems reduces the threshold current due to improved density of states distribution. New applications - This enables certain uses, currently speculative, but very much in the offing.

Integrated circuits are also known as microelectronic. The term micro derives from micro-fabrication technology, which embraces all highly sophisticated techniques like optical- and electron-beam lithography, metallization, implantation and etching that allow generating structures on the scale of one micrometer.

In the early 1970's, two scientists, Ari Aviram and Mark Ratner, began to envision electronic circuit elements made from single molecules and described in detail how they might function. This was the origin of the field of molecular electronics, now sometimes called molecular-scale electronics.

The emergence of molecular electronics and spintronics is providing a challenge to traditional electronic manufacturing techniques. Significant reduction in size and the sheer enormity of numbers in manufacturing are the benefits of molecular electronics. Scientists predict that computers will be assembled using molecules in the future, pushing technology far beyond the limits of silicon.

Satish P. Nair, Technical Insight Analyst says "The future of electronics is nano-sized, exciting nanofabrication techniques have unfolded different methods to engineer nanowires, quantum wells, and nanotubes which function as the building blocks of future nanoelectronic devices." The progress in carbon nanotube and semiconductor nanowire has provided researchers with a model against which to gauge future nanoscale devices and systems.

Adds Nair: "Molecular electronic can create devices that could be a thousand times smaller than current semiconductor-based devices. Molecular memories will also have a storage density million times that of today's best semiconductor chips."

Dramatic breakthroughs in molecular electronic by industry giant Hewlett Packard (HP) and other major developers validate these predictions. HP has created a new kind of minute circuit for computer chips using nanotechnology. The company's research laboratory also announced the development of the highest density electronically addressable memory to date.

Nair notes: "Research indicates that the time-to-market for commercial applications of Nanoelectronic-based devices is shrinking with the years. It is predicted that within the next five years, we will probably witness the first complete based-based device in the market."

Nanoelectronic areas being studied include the fabrication of atomic wires; Single Electron Tunnelling (SET) devices and atto-farad structures; and the study of spin-polarised electronics and magnetic nano-structures, all of which are likely to play an important part in future electronic devices. A study of the thermal motion of an isolated surface-trapped atom will also be carried out and its potential as a nano-scale noise thermometer investigated.

By growing nanowires that are 20 to 200 nanometers in diameter (one nanometer is one one-thousandth of a micrometer and human hair is typically 50 to 100 micrometers thick), researchers say they are closer to creating the circuitry required for nanoelectronic devices.

Research and development in nanoelectronic has been fuelled by huge investments by various national governments, as it is happing with nanotechnology in general. Countries in Europe and Asia, notably Japan and China are expecting to spend - and reportedly spending at the present - millions of dollars in the field of nanoelectronic.

Altawell.

©Altawell 2008