Cool rollerball-pen ink to draw circuits!

Two professors from the University of Illinois have combined their talents to use the idea of printing circuits onto non-standard materials by developing a conductive ink that can be used in a traditional roller ball ink pen to draw circuits by hand onto paper and other porous materials. In their paper published in Advanced Materials, team leads Jennifer Lewis, Jennifer Bernhard and colleagues describe how they were able to make a type of ink from silver nanoparticles that would remain a liquid while in the pen, but would dry like regular ink once applied. The pen could was then used to draw a functioning LCD display and an antenna.

To make the ink, the team produced silver nanoparticles by reducing a silver nitrate solution along with an acid to prevent the particles from growing too large. Afterwards the acid was removed and the viscosity of the ink modified using hydroxyethyl cellulose to get just the right consistency. The result is a sort of liquid metal that dries on contact and which can be used to conduct electricity, hence its ability to be used in the creation of a circuit.

  

Up till now, most research on printing circuits onto non-standard materials, such as paper, have been done using inkjet printers or even airbrushes. This new approach would allow circuits to be drawn quicker and much cheaper, or even on-the-fly, as no other hardware is needed. Such a low cost device might create a market for throwaway circuits or even super cheap batteries. Paper was used in the study because it is considered to be the most suitable non-standard material for printing circuits due to its wide availability, low cost, ability to be bent and shaped, and the fact that it is biodegradable.

The paper used in study was folded after testing to see how the circuit would hold up, and discovered it took folding several thousand times before the ink pathways were broken.

The team next plans to look into other types of materials that might be used to make conductive ink for their pen, hoping to open up the door to all kinds of inks that can be used for a wide variety of purposes.

Nanotechnology leads to massive increase in memory capacity

There are two very exciting recent advances in nanotechnology may soon result in a massive increase in memory capacities of your DVDs and iPods. Researchers at the Centre for Micro-Photonics at the Swinburne University of Technology in Victoria, Australia, created a new material that could lead to new discs that can store 10,000 times more data than your average DVDs.

The material is made up of layers of gold nanorods suspended in clear plastic spun flat on a glass substrate. Multiple data patterns can be written and read within the same area in the material without interfering with each other. Using three wavelengths and two polarizations of light, the Australian researchers have written six different patterns within the same area. They've further increased the storage density to 1.1 terabytes per cubic centimeter by writing data to stacks of as many as 10 nanorod layers.

Also Berkeley researcher  created a physical memory cell composed of an iron nanoparticle that can be moved back and forth in a nanotube. The position of the iron particle represents the state of the bit, which leads to very dense and highly stabile memory arrays, resulting in very long lifetime.