New type of Computing Uses Photopolymers and Light

A new type of computing, developed by researchers at McMaster University, uses a single-component, light-responsive system to perform computing operations without relying on external electrical power or processors.

The computing operation is performed by shining patterned bands of light and shadow through different facets of a photopolymer cube and reading the results that emerge. A researcher shines layered stripes of light through the top and sides of a glass case holding the polymer, which is roughly the size of a dice used in a board game.

McMaster researcher Fariha Mahmood uses new computing technology by shining patterned bands of light through a polymer cube. Courtesy of McMaster University.

The polymer begins as a liquid and transforms to a gel in response to the light. A neutral carrier beam passes through the back of the cube to a camera that reads the results as refracted by the material in the cube. This material forms into filaments that react to the patterns of light to produce a new pattern that expresses the computing results. Data input as binary (dark-bright) strings generate a unique distribution of filament geometries, which corresponds to the result of a specific operation.

The researchers said that the material in the cube reads and reacts intuitively to the light, in much the same way a plant would turn to the sun. The system responds to low-intensity, incandescent light, which, similar to ambient sunlight, comprises all visible wavelengths and is spatially and temporally incoherent.

The researchers were able to use their new process to perform simple addition and subtraction questions. “We’re very excited to be able to do addition and subtraction this way, and we are thinking of ways to do other computational functions,” said professor Kalaichelvi Saravanamuttu.

The form of computing is highly localized, needs no power source, and operates completely within the visible spectrum. The technology, part of the branch of chemistry called nonlinear dynamics, uses materials designed and manufactured to produce specific reactions to light. “These are autonomous materials that respond to stimuli and do intelligent operations,” Saravanamuttu said.

According to the researchers, the working principles of this photopolymer are transferable to other nonlinear systems and incoherent sources including LEDs. The work represents a new form of computing that someday could be used for more complex functions, possibly organized along the structures of neural networks.

The research was published in Nature Communications (https://doi.org/10.1038/s41467-019-10166-4).