Researchers at the Georgia Institute of Technology have reproduced muscle action of the human eye to control the camera systems using piezoelectric materials that generates electricity resulting from pressure.

Joshua Schultz, a Ph.D. candidate and his mentor assistant professor Jun Ueda, both from the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology are conducting the research to improve the operation of robots using similar muscle-like action. The study can also be used in further research on understanding the eye movements.

The researchers used piezoelectric cellular actuators, a biologically inspired actuator technology, that captures the robotic eye movements and make it move more like a real eye. Actuator is a type of a motor that moves or controls a system.

They use muscle-like piezoelectric actuators connected with many small actuator units in series or in parallel that is key to controlling the system. Piezoelectric actuators follow the basic principle of piezoelectric materials that expand or contract when electricity is applied to them. This way input signals are transformed into motion.

"For a robot to be truly bio-inspired, it should possess actuation, or motion generators, with properties in common with the musculature of biological organisms," said Schultz in a news release from the university.

"The actuators developed in our lab embody many properties in common with biological muscle, especially a cellular structure. Essentially, in the human eye muscles are controlled by neural impulses. Eventually, the actuators we are developing will be used to capture the kinematics and performance of the human eye," he said.

The researchers have developed a method that includes a camera positioner to understand the performance of the actuators. Although piezoelectric actuators have been used in various applications, their use has been very much limited in robotics applications.

"Each muscle-like actuator consists of a piezoelectric material and a nested hierarchical set of strain amplifying mechanisms," said Ueda adding that "Unlike traditional actuators, piezoelectric cellular actuators are governed by the working principles of muscles - namely, motion results by discretely activating, or recruiting, sets of active fibers, called motor units.

"Motor units are linked by flexible tissue, which serves a two-fold function," said Ueda. "It combines the action potential of each motor unit, and presents a compliant interface with the world, which is critical in unstructured environments," he said.

The research details were presented at the IEEE International Conference on Biomedical Robotics and Biomechatronics in Rome, Italy, last month. The researchers will work further on forming a design framework for highly integrated robotic systems.