Researchers realized liquid metal sensors along with AI for more natural prosthetic arms.
Humans rely on the touch receptors very much, and the lack of this sensation presents various challenges. Each human fingertip has more than 3000 touch receptors. Researchers are trying to fill the absence of these receptors with prosthetic limbs.
Researchers from Florida Atlantic University’s College of Engineering and Computer Science have recently incorporated stretchable tactile sensors using liquid metal on the fingertips of a prosthetic hand. They are aiming towards realizing a more natural feeling prosthetic hand interface. The study has been published in the journal Sensors.
The developed sensors are encapsulated within silicone-based elastomers. This approach provides significant advantages over traditional sensors, including high conductivity, compliance, flexibility and stretchability.
The researchers used individual fingertips on the prosthesis to distinguish between different speeds of a sliding motion along different textured surfaces. For each of the ten surfaces, 20 trials were collected to test the ability of the machine learning algorithms to distinguish between the ten different complex surfaces composed of randomly generated permutations of four different textures. Liquid metal sensors showed sensitivity among every surface and performed better overall by simultaneous reception.
“Significant research has been done on tactile sensors for artificial hands, but there is still a need for advances in lightweight, low-cost, robust multimodal tactile sensors,” said Erik Engeberg, Ph.D., senior author, an associate professor in the Department of Ocean and Mechanical Engineering and a member of the FAU Stiles-Nicholson Brain Institute and the FAU Institute for Sensing and Embedded Network Systems Engineering (I-SENSE), who conducted the study with first author and Ph.D. student Moaed A. Abd. “The tactile information from all the individual fingertips in our study provided the foundation for a higher hand-level of perception enabling the distinction between ten complex, multi-textured surfaces that would not have been possible using purely local information from an individual fingertip. We believe that these tactile details could be useful in the future to afford a more realistic experience for prosthetic hand users through an advanced haptic display, which could enrich the amputee-prosthesis interface and prevent amputees from abandoning their prosthetic hand.”