Last week the Ramón Areces Foundation and the Massachusetts Institute of Technology (MIT) held their fourth annual symposium, electronically, to present to Spanish society the avant-garde of what is being developed in this cutting-edge research center based in Boston . On this occasion, the three major experts in nanotechnology at MIT – two of them Spanish – have explained in two sessions held last Monday and Tuesday the promising advances that are taking place in the field of nanotechnology. Among other achievements, they have spoken of solar panels much more efficient and economical than the current ones, which are printable on paper or fabrics and which are rollable. They have also explained the developments of smart tissues or sensors that are gradually approaching the size of human cells.
Vladimir Bulovic, the founder and director of MIT.nano, considered the most innovative research center of this North American institution, has participated in this fourth congress at the Ramón Areces Foundation and MIT. Bulovic explained how there are no offices in that building: “the idea is that no one has a fixed place in it and thus the researchers, especially students, can rotate continuously”. Among other examples, Bulovic spoke of the importance of nanotechnology in making something as simple and important these days as protective masks. “Nanotechnology is already key to obtaining new materials, new medicines or new energy sources and it is going to revolutionize all these fields,” he said.
Photoelectric cells
And on the latter, he showed a new system of more efficient and economical photoelectric cells to capture the sun’s energy. “We have managed to print these cells on thin, roll-up material that can be deployed like carpets on the roof and also on the walls to capture sunlight when we are not at home. In this way, we will save costly installations, as we must bear in mind that two-thirds of the budget when we install rigid silicon solar panels are destined for the installation itself ”, said the director of MIT.nano. These printable solar cells, being so thin, versatile, light, transportable and, in addition, much more efficient, they will not have the risk of fracturing as is the case with silicon cells. In a skyscraper, for example, this technology could intrude on its windows, on its entire surface and be collecting energy from the sun without our knowing it. This system could also be very useful to provide electricity to populations that do not have access to this basic energy source.
For his part, Tomás Palacios, professor in the Department of Electrical Engineering and Computer Science at MIT, assured that we are in the most exciting and creative stage of electronics in the last 50 years because for the first time in decades Moore’s law already it does not dictate what to do. “At last we are free and we are forced to change the paradigm of electronics,” he said. His current research is focused on new electronic devices and applications for new semiconductor materials, such as graphene, molybdenum disulfide, and gallium nitride: The goal of his research group at MIT is to explore new paradigms that allow electronics to continue changing the world for the better.
Siliceous barriers
Palacios explained that traditional silicon-based electronics are currently facing five barriers that prevent it from advancing: the physical size of transistors is rapidly approaching the size of atoms; their performance does not improve at the expected rate, even if they reduce their size; access to system memory is much slower; These electronic elements consume more and more electrical energy and heat up more, and, in addition, the costs of the factories have increased a lot.
Painted this panorama that leaves behind Moore’s law, according to which processors reduce their size by half and double their capacity and the number of transistors every two years, Palacios believes that “something has to change.” And that is where the “extreme materials” in which it works come in: “Gallium nitride is a semiconductor used in all LED bulbs and with unique capabilities to control large amounts of current or voltage. We also have two-dimensional materials, which are extraordinary, with one atomic layer thick in the case of graphene and three in the case of molybdenum disulfide. Although they are the thinnest materials that exist, they are also the most resistant and possess extraordinary electronic properties ”.
Hardware accelerators
These materials are already showing that they can improve the performance of traditional processors as hardware accelerators. They are easy to integrate into them. There is great interest, for example, in the detection of infrared light, something that has applications in various fields such as night vision, medical diagnostic imaging tests or remote control of computers. These materials change their molecular structure, for example, from insulating to conducting, at a certain temperature… Palacios is convinced that future processors will continue to have silicon, but they will also need extreme materials such as gallium nitride to increase their performance. His research group is developing gallium nitride elements that will travel on spacecraft exploring Venus, where the ambient temperature is more than 500 degrees Celsius. “These circuits are also being investigated for integration into future supersonic aircraft, in which the temperature can exceed 800 degrees Celsius.”
The Spanish scientist from MIT is convinced that we are moving towards what he calls “ubiquitous electronics”, where all the objects around us will interact and be endowed with intelligence at different levels. But to take that step we first need to develop new electronic manufacturing methods. And they are already at it. As Palacios showed during his speech at the forum at the Ramón Areces Foundation, almost microscopic electronic circuits made from graphene can be integrated into the polymer material with which a drone with a 3D printer is manufactured. When the drone is in flight, these voltage sensors communicate the resistance of each specific area. This will be useful for incorporating this type of stress sensor into the fuselage of an aircraft.
Microprocessors in tissues
In the same way, these microprocessors can be integrated into the tissues. We are also witnessing a new generation of textile fibers. And so at MIT we can see a sweater that interacts with electronics in a new way by connecting with sensors to a neural network to use artificial intelligence (AI) and know what is happening around us. “Although there is still much to do, the border between the computer and the world around us is becoming increasingly blurred,” according to Palacios.
During this review of the latest in nanotechnology, the MIT researcher explained how there are already biomedical interfaces and audio processors that can be powered by WiFi waves. In each of our cells we find a wide variety of sensors and communication systems, with memory and methods to obtain energy … and all this in each of our cells and in a volume that is between one hundred and one thousand times less than the smallest of siliceous-based microsystems. Can we learn from nature and copy some of these ideas and develop it in electronic systems? That is what they are trying to do at MIT.
Electronic microsystems
Palacios explained how they are already working on a new group of electronic microsystems that are the size of biological cells. “We already have a prototype the size of 50 microns in diameter. I think it is one of the smallest electronic microsystems that has ever been manufactured, if not the smallest, and it is perfectly autonomous and has at least three chemical sensors, with logic, with a clock, with some memory … This new element it has the potential to transform electronics and it will allow us to explore many things ”. Regarding the size, he explained that these artificial cells are between 40 and 50 microns, but that they are already investigating a generation of only five microns.
In this case, at MIT.nano extreme materials such as molybdenum disulfide, gallium nitride and graphene are combined with siliceous. Millions of cells can be manufactured at the same time, and they are very versatile to float in the air for as long as necessary while detecting chemical compounds of interest. They can be introduced into plastic filaments of 3D printers to transfer this intelligence to objects, also mixed with polymers to change the optical and electrical properties of objects, and in the future these cells will be introduced inside our body to help us diagnose and treat endless diseases. This new generation opens up new opportunities for the electronics of the future, although as Tomás Palacios says, there is still a long way to go. And he insists: “we are at the most exciting moment in the history of electronics due to the confluence of new extreme materials.”
