Dr. Ting Xu (Credit: UC Berkeley)

Ting Xu, a researchers on the team from the University of California, explained that using a thin film of block copolymers, which are two or more chemically dissimilar polymer chains linked collectively, the molecules in the material have assembled themselves into an exceptionally accurate, equidistant pattern when distributed on a surface. Prior to this outcome, scientists found it difficult to create this precise characteristic in semiconductor purposes as the strictly assembled molecules cannot keep their accurate positions as the size of the surface increases.

 

The strength of the formation is essential because if the formation fails, the domains cannot be read or written to, making it a futile form of data storage. “I expect that the new method we developed will transform the microelectronic and storage industries, and open up vistas for entirely new applications,” said co-lead investigator Thomas Russell, from UMass Amherst, and one of the world's leading experts on the behaviour of polymers. “This work could possibly be translated into the production of more energy-efficient photovoltaic cells, for instance.”

 

To solve the surface area issue the team developed a simple solution of layering the film of block copolymers onto the surface of a commercially available sapphire crystal. The crystal is then cut at an angle and heated to 1,300 to 1,500 degrees Centigrade (2,372 to 2,732 degrees Fahrenheit) for 24 hours. At this point, its surface reorganizes itself into a very sequential model of saw tooth ridges that can be subsequently utilized to direct the self-assembly of the block polymers.

 

The sawtooth ridges formed by cutting and heating a sapphire crystal, shown at top, serves to guide the self-assembly of nanoscale elements into an ordered pattern over arbitrarily large surfaces. Researchers say the new, easy-to-implement technique may transform the data storage industry. (Dong Hyun Lee/UMass Amherst)

Using this method, the researchers achieved defect-free arrays of nanoscopic elements as small as 3 nanometers, leading up to densities of 10 terabits per square inch. One terabit is equal to 1 trillion bits, or 125GB. There is no real limit to the surface size and the crystals can be manufactured in a variety of sizes. To add to the flexibility, the angle and depth of the saw tooth ridges can be effortlessly adjusted by varying the temperature at which the crystal is heated to polish up the required pattern.

 

“We can generate nearly perfect arrays over macroscopic surfaces where the density is over 15 times higher than anything achieved before,” said Russell. “With that order of density, one could get a high-definition picture on a screen the size of a JumboTron.”  

 

Xu presented an analogy of how easy it is to make dozens of soldiers stand in perfect formation in an area the size of a classroom; each person equidistant from the other. Take that a step further and just imagine having tens of trillions of individuals do so on the field in a football stadium. “Using this crystal surface as a guide is like giving the soldiers a marker so they know where to stand,” Xu added.

 

TFOT has previously written about tuning graphene's nature to mass produce graphene-based nanoelectronics and also about nanowires which make high capacity storage devices that may become a key factor in next generation high storage magnetic devices. You can also check out our article about new nanoscale technology for memory storage; a new type of computer memory which some say will boost the performance, capacity, and battery life of consumer electronics such as digital cameras and laptops.

Additional information on this future storage can be obtained at UC Berkeley’s website.