Programmable computers that use chemical reactions to process information could solve problems faster than conventional computers. And, they may better mimic the brain than their electronic counterparts.
Traditional computers are built from small components, such as resistors and transistors, that manipulate electronic signals in such a way as to be able to store and process information. In 2019, Lee Cronin and his colleagues at the University of Glasgow in the UK built a chemical version of a computer using . Now, the researchers have gone a step further by figuring out how to program the chemical computer to solve concrete problems.
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The machine is a plastic grid of interconnected chambers, each filled with a liquid mixture of two different acids and a salt made of potassium and bromine. Mechanical stirrers agitate the liquid, which jumpstarts a chemical reaction. To program a specific problem, the researchers adjust the speed of each stirrer, which controls the rate of the reaction in each cell.
As the reaction goes on, the cells alternately flash either red or blue light. The colour flashes in different cells are analogous to the 1s and 0s used in electronic computers. So a chemical computation looks like a sequence of colourful flashes across the grid. A video camera records all the reds and blues and uses that information to adjust the stirrers to continue the computation.
Mistakes in computation can happen if any cells get out of sync with their neighbours and start flashing colours too quickly or slowly. The researchers placed additional, smaller stirrers between each neighbouring pair of cells to allow them to interact and keep each other in sync. 聽Cronin says that programming this sort of error correction is somewhat easier with a chemical computer than electronic and quantum computers.
鈥淲e built a digital mechanical interface to program the chemistry. And then the chemistry does computation,鈥� says Cronin. 鈥淎ll you do is you basically fill the grid up with the chemicals.鈥�
So far, the researchers have used their chemical computer to solve some simple problems, such as the travelling salesperson problem which involves finding the shortest route between a list of different places.
Since each cell acts as a memory and a mini processor at the same time, the computer is particularly well suited for performing many calculations all at once, says at the University of the West of England, Bristol. This could make it good at solving optimisation problems, like the travelling salesperson problem, which slow down conventional computers because they require lots of memory.
The new device is around 30 by 30 centimetres in size. Figuring out how to make it smaller or to put it onto chips could also make it easier to use outside the lab.
Cronin and his colleagues are also interested in connecting the chemical computer with biological life. A brain is, in a way, a computer that uses chemical processes to make sense of electrical inputs from organs such as eyes, he says. In both brains and the chemical computer, an input is translated into a whole system of ongoing, interconnected chemical reactions, so mastering the chemical computer may help researchers better understand the evolution of brains.
搁别蹿别谤别苍肠别:听arXiv,
