Researchers have developed a new process for reliable self-assembly of colloids in a diamond formation.

The long-awaited photonic technology will change the way scientists develop and use optical technologies in the next decade.

Colloidal diamonds have been the dream of researchers since the 1990s. These structures – the shapes of small objects that are stable and self-assembled – have the ability to make light waves as useful as electrons in computing and keep their promise for many other applications. Although the concept of colloidal diamonds was developed decades ago, so far – no one has been able to build structures reliably.

“Most researchers have given up on telling you the truth. We may still be the only team in the world.”

Researchers led by David Pine, a professor of chemical and biomolecular engineering at the Tandon School of Engineering at New York University and physics professor at NUYU, have developed a new process for reliable self-assembly of colloids in diamond formation. The measurable fabrication of such structures.

Discovery, appears in Nature, Which can open the door to high-efficiency optical circuits leading to the advancement of optical computers and lasers, as well as more reliable and cheaper light filters than ever before.

Pine and colleagues, including Ming Xin He, a postdoctoral researcher in the NUU Department of Physics, and Stefano Sakanna, an associate professor of chemistry, study colloids and the ways in which they can be formed over decades.

These objects, made up of hundreds of spheres smaller than the diameter of human hair, can be adjusted differently Crystal forms It depends on how the spheres connect to each other. Each colloid attaches to another, a series of strands of DNA grafted onto the surface of colloids that act as a kind of molecular velcro. When colloids collide with each other in a liquid bath, DNA snags and colloids bond. Depending on where the DNA attaches to the colloid, they can spontaneously form complex structures.

This process was used to create strings of colloids and colloids in a cubic formation. But these structures did not produce Holy Grail PhotonicsBand gap for visible light. Just as a semiconductor filters electrons in a circuit, a band gap filters out certain wavelengths of light. Filtering light in this way can be reliably achieved if the colloids are arranged in a diamond formation, a process that is very difficult and expensive to perform on a commercial scale.

“There is a great desire among engineers to build a diamond structure,” says Pine. “Most researchers have given it up to tell you the truth. We may still be the only group in the world. So I think the publication of the essay will be something that will surprise the society. ”

Investigators found that a sterile interlock system could be used to automatically generate the required stagnant bonds to enable this structure.

When these pyramidal colloids were aligned with each other, they were connected in the orientation required to create a diamond formation. Instead of going through the arduous and expensive process of constructing these structures using nanomachines, this system allows the colloids to form themselves without the need for external intervention. In addition, the diamond structure remains stable even after the liquid is removed.

The discovery was made because he was a graduate student at NU Tandon at the time and noticed an unusual feature of the colloids that synthesize in a pyramidal formation. He and his colleagues explained all the ways to connect these structures. When they happened in a particular interconnected structure, they realized that they were in the right way. “After creating all these models, we saw that we created diamonds,” he says.

“Dr. Long-term performance of the first self-assembled colloidal diamond lattice pine, which unlocks new research and development opportunities for key defense technology departments that can benefit from 3D photonic crystals, ”said Evan Runnerstrom, Program Manager at the Army Research Office (ARO). , A component of the Army Research Laboratory of the U.S. Army Combat Capacity Development Command.

Future developments include applications for high-efficiency lasers that reduce the weight and energy requirement for precision sensors and directed energy systems; Accurate control of light for 3D integrated photonic circuits or optical signature management.

The team is now focused on seeing how these colloidal diamonds can be used in a practical setting. They are already creating materials using new structures that can filter optical wavelengths to prove their usability in future technologies.

The research was supported by the U.S. Army Research Office and the National Science Foundation. More researchers on the project are from the Center for Research Paul Pascal-CNRS in Pesach, France, and Sungkungwon University in Suwon, South Korea.

Source: NYU