A team at Georgia State University have developed an “electronic eye” that can provide color vision for microrobots. While the technology should be useful for medical robots, it could also make possible color perception technology for the visually impaired and could act as a component of artificial eyes. The technology relies on a stack of van der Waals semiconductors to sense red, green, and blue light. Stacking the semi-conductors allowed the researchers to decrease the size of the artificial vision system. While still in its infancy, the technology could pave the way for more advanced electronic eyes, which would be very useful for the visually impaired.
“It is well-known that more than 80 percent of the information is captured by vision in research, industry, medication, and our daily life,” said Sidong Lei, a researcher involved in the study. “The ultimate purpose of our research is to develop a micro-scale camera for microrobots that can enter narrow spaces that are intangible by current means, and open up new horizons in medical diagnosis, environmental study, manufacturing, archaeology, and more.”
Previously designed color sensors are bulky, meaning they are unsuitable for inclusion in microrobots or artificial eyes. A key challenge in designing this new technology was miniaturization. Moreover, previous technologies lacked accuracy in color detection, so the researchers aimed to improve on this as well.
“The new functionality achieved in our image sensor architecture all depends on the rapid progress of van der Waals semiconductors during recent years,” said Ningxin Li, another researcher involved in the study. “Compared with conventional semiconductors, such as silicon, we can precisely control the van der Waals material band structure, thickness, and other critical parameters to sense the red, green, and blue colors.”
Interestingly, the Georgia Tech researchers believe that the technology has future potential for the visually impaired. “This technology is crucial for the development of biomimetic electronic eyes and also other neuromorphic prosthetic devices,” said Li. “High-quality color sensing and image recognition function may bring new possibilities of colorful item perception for the visually impaired in the future.”
The team successfully miniaturized the device so that it is significantly smaller than pre-existing color sensors. “The ultra-thinness, mechanical flexibility, and chemical stability of these new semiconductor materials allow us to stack them in arbitrary orders,” said Li. “So, we are actually introducing a three-dimensional integration strategy in contrast to the current planar micro-electronics layout. The higher integration density is the main reason why our device architecture can accelerate the downscaling of cameras.”
Study in ACS Nano: van der Waals Semiconductor Empowered Vertical Color Sensor
