Biomimetic robotic skin implemented with hydrogel-elastomer hybrids and tomographic imaging methods

Human skin perceives physical stimuli applied to the body and mitigates
the risk of physical interaction through its soft and resilient mechanical
properties. Social robots would benefit from whole-body robotic skin (or
tactile sensors) resembling human skin in realizing a safe, intuitive, and
contact-rich interaction with humans. However, existing soft tactile
sensors show several drawbacks (complex structure, poor scalability, and
fragility), which limit their application in whole-body robotic skin.
Here, we introduce biomimetic robotic skin based on hydrogel-elastomer
hybrids and tomographic imaging. The developed skin consists of tough
hydrogel and silicone elastomer forming a skin-inspired multilayer
structure, achieving sufficient softness and resilience for protection.
The sensor structure can also be easily repaired with adhesives even after
severe damage (incision). For multimodal tactile sensation, electrodes and
microphones are deployed in the sensor structure to measure local
resistance changes and vibration due to touch. The ionic hydrogel layer is
deformed due to an external force, and the resulting local conductivity
changes are measured via electrodes. The microphones also detect the
vibration generated from touch to determine the location and type of
dynamic tactile stimuli. The measurement data are then converted into
multimodal tactile information through tomographic imaging and deep neural
networks. We further implement a sensorized cosmetic prosthesis,
demonstrating that our design could be used to implement deformable or
complex-shaped robotic skin.