Most of the robots accomplish grasping and tactile sensing with aid of a motorized device that can be highly rigid and bulky. The researchers are from Cornell University who has devised a method for a soft robot to feel its surroundings internally in the similar way as the humans perform.
A team headed by Robert Shepherd, an assistant lecturer of aerospace and mechanical engineering and principal investigator of Organic Robotics Lab has introduced a paper detailing on how stretchable optical waveguides function as elongation, curvature and stretchable force sensors in a soft robotic hand.
The Doctoral student Huichan Zhao is head author of ‘Optoelectronically innervated soft prosthetic hand through stretchable optical waveguides that is featured in the recent publication of the edition. “Most of the robotics these days has sensors on the external body that identify things from the surface, so they can really identify forces being transferred through the thickness of the robot, a lot similar to all organisms do when they feel pain, for instance.”
Optical waveguides has been in use since the early 1970s for multiple sensing functions, comprising position, tactile and acoustic. Engineering was conventionally a complex process but the advent over the last 20 years of soft lithography and a 3 dimensional printing process has resulted in the development of elastomeric sensors that are conveniently produced and integrated into a soft robotic application
The entire group of Shephers has employed a four – step soft lithography procedure to generate the core through which the white light propogates and the entire cladding exterior surface of the waveguide that also homes the LED or light emitting diode and the photodiode.
The more and bigger are the prosthetic hand deforms, the more volume of light is lost through the internal core. That variable loss of light as identified by the photodiode is that enables the prosthesis to ‘sense’ and identify its surroundings.
“If no volume of light was lost when we bend the prosthesis, we would not be able to obtain any volume of information about the state of the sensor,” says Shepherd. “The total volume of loss is dependent and how it is bent.”
The entire group is now using optoelectronic prosthesis to perform a range of tasks, comprising probing and grasping for both of the shapes and textures. Most vitally and notably the robotic hand was even able to scan three tomatoes and determine out of them, by level of softness that which one was the ripest among them. The researchers intend to further carry the study on various other objects and elements before concluding it on a final note.
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