Scientific breakthrough may mean stronger smartphone screens

By Mark Waghorn via SWNS

Stronger smartphone and computer screens could be on the horizon after a breakthrough by scientists.

An international team developed a better way to build tiny particles called 'colloids' - that form the backbone of a vast range of products.

They showed they can simply use the shape to make interesting designs - regardless of other properties.

Lead author Dr. Laura Rossi, of Delft University of Technology, The Netherlands, said: "This is striking, because it opens up a completely new way to think about materials design."

Colloids - tiny particles suspended in a liquid - are also used in paints, cosmetics, sun blocks, pharmaceuticals and even foods.

They are a few nanometres to a few microns in size with a variety of molecules that have different properties depending on what they are made from.

Explained Dr. Rossi: "Under certain circumstances, colloids can behave like atoms and molecules, but their interactions are less strong.

"That makes them promising building blocks for new materials, for example for interactive materials that can adapt their properties to their environment."

If left alone, her cube-shaped colloids made from glass assembled themselves into simple structures like distorted cubic and hexagonal lattices.

But instead of going immediately to the final structure, Dr Rossi and colleagues took small groups and combined them into bigger pieces.

They ended up with a different final form and properties than the self-assembled counterpart.

Dr. Rossi said: "From a chemistry point of view, we always focus on how we can produce a certain type of colloid.

"In this study, we have shifted our focus to how can we use the colloids that are already available to make interesting building blocks?"

Almost every manufacturing process uses colloids in some form - ranging from making mayonnaise to latex, ceramics, paper coatings and all sorts of lotions and potions.

But until now, companies have had to rely heavily on experience to judge the critical
properties of a suspension - the size of the suspended particles and their
electrical charge.

Getting it wrong can mean overusing ingredients, ruining an entire batch or producing an inferior product. The ultimate goal is to design complex colloidal structures on demand.

Co-author Dr. Greg van Anders, of Queen's University, Kingston, Ontario, said: "What we found here is very important because, for possible applications, we need to have procedures that can be scaled up which is something that will be hard to achieve with most currently available approaches.

"The basic ability to pre-assemble identical pieces from different building blocks, and have them make the same structure, or to take the same building block and pre-assemble different pieces that make different structures, are really the basic 'chess moves' for engineering complex structures."

The findings, published in the journal Science Advances, have a host of potential applications.

Dr. Rossi said: "We found the density of the structure we prepared was much lower than the density of the structure you would obtain by using the starting building blocks.

"So you can think about strong but lightweight materials for transportation."

Her group built clusters of colloids in the lab. Then they relied on the team of Dr van Anders to build the final structure out of pre-assembled clusters with a computer simulation.

Dr. Rossi said: "With these kinds of projects, it is great to be able to team up with others who can run simulations, not only to understand what is happening in-depth, but also to test how big the chance of a successful lab experiment will be.

"And in this case, we got very convincing results that we were understanding the design process well and that the resulting material can be useful."

The next step will be to actually build the final structure made from the groups of colloids in the lab.

Dr. Rossi added: “After seeing these results, I am confident it can be done. It would be great to have a physical version of this material and hold it in my hand."