Whether it's used for a robot to help out around the house or for a prosthesis, researchers at Carnegie Mellon University have developed a three-fingered soft robotic hand with multiple embedded fiber optic sensors.
Each finger of the hand contains 14 fiber optic sensors.
“[They] basically detect very small strain changes, so when you stretch a little bit or you compress it detects the strain changes,” said Yong-Lae Park, assistant professor in CMU’s Robotic Institute
The robotic finger is composed of two parts: a bone structure made of rigid plastic and a soft skin made of silicon. Each detects force and strain changes. Only sensors in the soft skin layer detect the location of the contact between the finger and the object that is touched.
According to Park, because this particular hand uses fiber optics and not electronics, electromagnetic interference is not an issue. The hand also won’t have a lot of wires coming out of it but rather a few fibers each containing multiple sensors.
He says the robotic hand could be used for those needing a prosthetic hand, but the research group primarily looked at how it could be used in robotics.
“Some kind of humanoid robot, but not [a] really complicated humanoid robot, but [with a] relatively simple mechanism which has good sensing capability,” said Park.
In other words, the hand could be used as part of a helper robot in the homes of those who can’t perform certain tasks on their own.
“For elderly people or disabled people or weak people who don’t have good mobility or control for their muscles,” said Park.
The robot could use the developed hand to change clothes or feed that person.
According to Park, the challenge with robotics being used in everyday life is transitioning away from a controlled environment, where the robot has routine and preprogrammed tasks, where they know what they need to do and know the environment. These types of robots have a limited number of sensors and only have enough for their required tasks.
“To be more autonomous and responsive to our world then the robot needs to be really equipped with a lot of sensors,” said Park.
He says it's difficult to predict what might happen in everyday life since the environment isn’t controlled, so the hand’s sensors need to accommodate variables.
Researchers have also developed a new type of stretchable optical sensor, not yet implanted in the current version of the hand. Currently, fiber optics has an elasticity problem because they are made of glass. The team is currently working on implementing a robotic skin which can stretch twice it’s current length, according to Park.
The project is in the developmental stage, and Park said more time and effort is needed to test and improve the performance anywhere between three and five years to have a “pretty mature technology.”
