Researchers develop a technique to fabricate large squares of graphene riddled with controlled holes

Researchers at MIT have found a way to directly “pinprick” microscopic holes into graphene as the material is grown in the lab. Using this technique, they have fabricated relatively large sheets of graphene (roughly the size of a postage stamp), with pores that could make filtering certain molecules out of solutions vastly more efficient.

Holes would typically be considered unwanted defects, but the MIT team has found that certain defects in graphene can be an advantage in fields such as dialysis. Typically, much thicker polymer membranes are used in laboratories to filter out specific molecules from solution, such as proteins, amino acids, chemicals, and salts. If it could be tailored with selectively-sized pores that let through certain molecules but not others, graphene could substantially improve separation membrane technology.

Graphenea and MIT develop sensors based on graphene and porphyrins for ammonia detection

MIT and Graphenea have developed an array of graphene sensors for sensitive and selective detection of ammonia. The array consists of 160 graphene pixels, allowing large statistics that result in improved sensing performance. The sensors are extensively tested for various real-life operational conditions, which seems to be a step forward to practical use.

Graphenenea and MIT's graphene and porphyrins sensors for ammonia detection image

The sensors are built by attaching porphyrins, a class of organic molecules, to the graphene surface. Porphyrins are particularly well-matched to graphene sensors because they provide excellent sensitivity while producing minimal perturbation to graphene’s outstanding electrical properties. When ammonia molecules attach to porphyrins, the compound becomes a strong dipole that changes electrical properties of the graphene. This electrical change is detected as a sign of the presence of ammonia.

Graphene enables novel thermal camouflage system

Researchers from Bilkent University and Izmir Institute of Technology in Turkey, MIT and University of Manchester have developed a system that can reconfigure its thermal appearance to blend in with varying temperatures in a matter of seconds.

Graphene thermal camouflage system image

Previously, scientists have tried to develop thermal camouflage for various applications, but they have encountered problems such as slow response speed, lack of adaptability to different temperatures and the requirement for rigid materials. The team in this research wanted to develop a fast, rapidly adaptable and flexible material.

Researchers develop graphene-based bolometer that is fast, simple and covers more wavelengths

A team of researchers at MIT, Raytheon BBN Technologies and Columbia University have used graphene to design a fast yet highly sensitive bolometer that can work at room temperature and may even be less expensive. Bolometers are devices that monitor electromagnetic radiation through heating of an absorbing material. Most such devices have limited bandwidth and must be operated at ultralow temperatures, which damages their usefulness.

Fast and simple graphene bolometer image

The findings of this work could help pave the way toward new kinds of astronomical observatories for long-wavelength emissions, new heat sensors for buildings, and even new kinds of quantum sensing and information processing devices, the multidisciplinary research team says.

Researchers develop a graphene-based approach to making light interact with matter

Researchers at MIT and Israel's Technion have used graphene to devise a new way of enhancing the interactions between light and matter, in a work that could someday lead to more efficient solar cells that collect a wider range of light wavelengths, and new kinds of lasers and light-emitting diodes (LEDs) that could have fully tunable color emissions.

Researchers devise new way to make light interact with matter image

The basic principle behind the new approach is a way to get the momentum of light particles (photons) to more closely match that of electrons, which is normally much greater. This huge difference in momentum normally causes these particles to interact very weakly; bringing their momenta closer together enables much greater control over their interactions, which could enable new kinds of basic research on these processes as well as a host of new applications, the researchers say.

XFNANO: Graphene and graphene-like materials since 2009 XFNANO: Graphene and graphene-like materials since 2009