Nature's new molecular device has unprecedented reconfigurability, reminiscent of the plasticity of the brain

This is reminiscent of the plasticity of connections in the human brain.
The device can be dynamically reconfigured for different computing tasks by simply changing the applied voltage
.

In addition, just like nerve cells can store memories, this device can also retain information for future retrieval and processing

"The brain has an extraordinary ability to change the wiring around it by establishing and destroying connections between nerve cells
.

It is extremely challenging to achieve something comparable in a physical system," Texas A&M University Said Dr.

Dr.
T.
Venkatesan, director of the Center for Quantum Research and Technology (CQRT) at the University of Oklahoma, a scientific subsidiary of the Gaithersburg National Institute of Standards and Technology, and an adjunct professor of electronic and computer engineering at the National University of Singapore, they added that their In the future, molecular devices may help design next-generation processing chips to increase computing power and speed, but the energy consumption is greatly reduced
.

Whether it is a familiar laptop or a complex supercomputer, digital technology faces a common enemy, the von Neumann bottleneck
.

This delay in computational processing is a result of the current computer architecture, in which the memory containing data and programs is physically separated from the processor

As an alternative to the traditional electronic components used to design memory cells and processors, a device called a memristor provides a way to bypass the von Neumann bottleneck
.

Memristors, such as those made of niobium dioxide and vanadium dioxide, transform from an insulator to a conductor at a certain temperature

However, despite many advantages, these metal oxide memristors are made of rare earth elements and can only work in a limited temperature range
.

Williams said, therefore, people have been looking for organic molecules with similar memory functions

Dr.
Sreebrata Goswami, a professor at the Indian Association for the Cultivation of Science, designed the materials used in this work
.

The compound has a central metal atom (iron) combined with three phenylazopyridine organic molecules called ligands

"It's like an electron sponge that can reversibly absorb up to 6 electrons, resulting in 7 different redox states," Sreebrata said
.

"The interconnection between these states is the key behind the reconfigurability shown in this work

Dr.
Sreetosh Goswami, a researcher from the National University of Singapore (National University of Singapore), designed this project.
He created a microcircuit composed of a 40-nanometer molecular film.
It is sandwiched between a layer of gold on the top and a gold-plated nanodisk and indium tin oxide on the bottom
.

When a negative voltage was applied to the device, sreettosh saw an unprecedented current-voltage curve
.

Unlike metal oxide memory resistors, metal oxide memory resistors can be converted from metal to insulator under a fixed voltage, while organic molecular devices can be converted from insulator to conductor under several discrete sequential voltages

"So, if you think of this device as a switch, when we sweep the voltage to more negative, the device first turns on to off, then off to on, then on to off, and then back to on
.
I would say that we were just blown out of our seats
.
" "We have to convince ourselves that what we see is real
.
"

Sreetosh and Sreebrata used an imaging technique called Raman spectroscopy to study the molecular mechanism behind this strange switching behavior
.
In particular, they look for spectral features in the vibrational motion of organic molecules to explain multiple transitions
.
Their research shows that the negative sweep voltage triggers a series of reduction or electron acquisition events on the ligand on the molecule, causing the molecule to switch between the off state and the on state
.

Next, in order to mathematically describe the current-voltage distribution of extremely complex molecular devices, Williams deviated from the traditional method based on basic physical equations
.
Instead, he used a decision tree algorithm to describe the behavior of the molecule and used the "if-then-other" statement, which is a line of code that is common in many computer programs (especially digital games)
.

"The structure of a video game is that your character does something and then something happens
.
So, if you write it in a computer algorithm, they are if-then-else statements
.
" "Here, because of the applied voltage , The molecule went from opening to closing.
At this time, I had a brainstorm and used a decision tree to describe these devices.
The effect was very good
.
"

But researchers go a step further and use these molecular devices to run programs to perform different real-world computing tasks
.
Sreettosh has proved through experiments that their device can complete quite complex calculations in one time step, and then reprogram it to perform another task in the next instant
.

"This is weird; what our devices do is similar to what the brain does, but in a very different way," Sritosh said
.
"When you are learning new things or making decisions, the brain can actually reconfigure and change the physical wiring around it
.
Similarly, we can logically reprogram or reconfigure the device by giving it a different voltage pulse
.
"

Venkatesan pointed out that thousands of transistors are needed to perform the same computational functions as a decision tree different from a molecular device
.
Therefore, he said that their technology may first be used in handheld devices, such as cell phones and sensors, as well as other power-limited applications
.

Other contributors to the study include Dr.
Abhijeet Patra and Dr.
Ariando from the National University of Singapore; Dr.
Rajib Pramanick and Dr.
Santi Prasad Rath from the Science Training Association of India; Dr.
Martin Foltin from Hewlett Packard Enterprise, Colorado; and from Limerick, Ireland Dr.
Damian Thompson of the University
.

Venkatesan said that this research shows the future findings of this collaborative team, which will include the Nanoscience and Engineering Center of the Indian Institute of Science and the Microsystems and Nanotechnology Department of NIST
.

This multidisciplinary and transnational research was supported by the Singapore National Research Foundation's competitive research project; the Indian Science and Engineering Research Council; the X-Grants project of the Presidential Excellence Fund of Texas A&M University; the Singapore Advanced Manufacturing and Engineering Personal Research Fund Funded science, technology and research; the start-up funding of the University of Oklahoma (CQRT University of Oklahoma); and the Science Foundation of Ireland
.

Journal Reference :

1. Sreetosh Goswami, Rajib Pramanick, Abhijeet Patra, Santi Prasad Rath, Martin Foltin, A.
   Ariando, Damien Thompson, T.
   Venkatesan, Sreebrata Goswami, R.
   Stanley Williams.
   Decision trees within a molecular memristor .
   Nature , 2021; 597 (7874) : 51 DOI: 10.
   1038/s41586-021-03748-0