Analog VLSI design, neural networks

Albert H. Titus

Dr. Titus' research interests include analog VLSI implementations of artificial vision, hardware and software artificial neural networks, hardware implementations of decision-making aids, optoelectronics and integrated sensor systems. He is funded by the National Science Foundation, Johnson and Johnson, Intel, and Ultrscan.

              One of his research projects involves creating electronic vision systems that could be used in robots to explore the oceans, outer space, and harsh environments. Professor Titus and his colleagues developed an experimental version of the o-retina chip, which is about the size of a narrow Post-it Note. The chip acts as a retina, a sensory membrane in the eye that distills relevant visual information to be sent to the brain.

              "We'd like to be able to explore new things in a more intelligent way, to have a vision system that perceives its environment and makes decisions without a human always telling it what to do," says Titus. One big challenge is figuring out how the brain uses information to understand and reconstitute an image, and then translating that process onto a chip. The octopus retina provides a simple, yet elegant visual system which, Titus says, is relatively easy to simulate in silicon.

By using a sea creature, and later broadening optical studies to an eagle or hawk, Titus hopes to create smarter vision systems that see the world in different ways. He plans to electronically inter-connect the structure and functions of different types of animals' eyes and brains, for example, an eagle's brain and an octopus's eyes.

"Different animals have different visual structures with different properties for how they see the world," Titus says. "If we want to develop a chip that can see far distances, we should mimic the visual system of an eagle."

Octopuses, which live in murky warm waters, have large eyes on either side of the head. Like the octopus eye, the o-retina chip sees horizontally and vertically. It uses brightness, size, orientation, and shape to distinguish objects. Also like the octopus, the o-retina cannot see diagonal or horizontally mirrored images such as the letter X. Future versions of the chip aim to include the ability to see polarized light, an important aspect of the octopus visual system.

The o-retina is not sophisticated enough to see a person, but Titus says it is not always necessary during exploration to see an object or scene in detail.

Titus's work has attracted the attention of other scientists. "Silicon-retina technology will have widespread use in remote-site exploration, wireless sensor networks and many other places where one needs cheap 'information-extracting' visual interfaces," says Andreas Andreou, an expert on silicon retinas at Johns Hopkins University.

             

Using direct e-beam writing, his student created the following micron-sized UB logo.