Brain-inspired image sensor can detect miniscule objects: IISc study

Source: The post is based on the article “Brain-inspired image sensor can detect miniscule objects: IISc study” published in The Hindu on 22nd February 2023

What is the News?

Researchers at the Indian Institute of Science (IISc) have shown how a brain-inspired image sensor can go beyond the diffraction limit of light to detect miniscule objects such as cellular components or nanoparticles invisible to current microscopes.

Background

Since the invention of optical microscopes, scientists have been trying to surpass a barrier called the diffraction limit, which means that the microscope cannot distinguish between two objects if they are smaller than a certain size (typically 200-300 nanometers). 

Their efforts have largely focused on either modifying the molecules being imaged or developing better illumination strategies.

What have the researchers developed?

Researchers have developed a novel technique which combines optical microscopy with a neuromorphic camera and machine learning algorithms to detect miniscule objects such as cellular components or nanoparticles which are invisible to current microscopes.

The neuromorphic camera used for this technique mimics the way the human retina converts light into electrical impulses and has several advantages over conventional cameras. 

In a typical camera, each pixel captures the intensity of light falling on it for the entire exposure time that the camera focuses on the object, and all these pixels are pooled together to reconstruct an image of the object. 

In neuromorphic cameras, each pixel operates independently and asynchronously, generating events or spikes only when there is a change in the intensity of light falling on that pixel. 

This generates sparse and lower amounts of data compared to traditional cameras, which capture every pixel value at a fixed rate, regardless of whether there is any change in the scene.

Significance of this technique: This study presents a major step forward in pinpointing objects smaller than 50 nanometers in size.