In a significant leap for the future of computing, researchers at the Indian Institute of Science (IISc) in Bengaluru have developed a new class of ultra-small electronic devices that can adapt their function on the fly. This innovation promises to push technology beyond the limits of conventional silicon chips.
One Device, Multiple Functions
The team has successfully demonstrated tiny devices built from specially engineered molecules. These molecular-scale systems can switch their role based on the electrical signal they receive. The same physical device can act as a memory unit, a logic gate for calculations, an analogue processor, or even an artificial synapse that mimics the learning and forgetting processes of the human brain. This adaptability is a rare and powerful feature in electronic materials.
Solving Two Challenges at Once
For decades, scientists have pursued molecular electronics to create smaller components than silicon allows. However, controlling the complex interactions within molecules reliably has been a major hurdle. Separately, the field of neuromorphic computing, which aims to build brain-inspired hardware, has struggled to find materials that inherently combine memory and processing.
The IISc work, published in a study bridging chemistry, physics, and electrical engineering, suggests a solution to both problems. The research was led by Sreetosh Goswami, an assistant professor at the Centre for Nano Science and Engineering (CeNSE). The team designed and synthesized 17 different variants of molecular complexes based on the metal ruthenium.
Chemistry Drives Computation
By meticulously altering the chemical ligands and surrounding ions in these molecules, the researchers could precisely tune how electrons move through thin films made of this material. "It is rare to see adaptability at this level in electronic materials," said Goswami. "Here, chemical design directly determines how computation happens."
These subtle chemical tweaks allowed the devices to exhibit a wide spectrum of electronic behaviors. They could show sharp, digital on-off switches or smooth, analogue responses across many levels of electrical conductance.
The molecular synthesis was carried out by Pradip Ghosh, a Ramanujan Fellow at CeNSE, and former doctoral student Santi Prasad Rath. Device fabrication and testing were led by the study's first author, PhD student Pallavi Gaur. "What stood out was how much functionality was hidden in the same system," Gaur noted. "With the right chemistry, one device can store information, process it, or even learn and forget."
This breakthrough paves the way for a future where hardware can be dynamically reconfigured for different tasks, leading to more efficient and powerful computers that operate in ways fundamentally different from today's rigid silicon-based systems.
