3D-printed electronic skin promises human-machine interaction

With more than 1,000 nerve endings, human skin constitutes the brain’s largest sensory connection to the outside world, providing a wealth of feedback via touch, temperature and pressure. While these complex characteristics make the skin a vital organ, they also make its reproduction difficult.

Using nano-engineered hydrogels that feature tunable electronic and thermal biosensing capabilities, researchers at Texas A&M University have developed a 3D-printed electronic skin (E-skin) that can bend, stretch, and feel like human skin.

“The ability to replicate the sense of touch and integrate it into various technologies opens up new possibilities for human-machine interaction and advanced sensory experiences,” said Dr. Akhilesh Gaharwar, professor and research director in the Department of biomedical genius. “This has the potential to revolutionize industries and improve the quality of life for people with disabilities.”

Future uses for E-skin are vast, including wearable health devices that continuously monitor vital signs such as movement, temperature, heart rate and blood pressure, providing feedback to and helping users improve their motor skills and coordination.

“The inspiration behind the development of E-skin is rooted in the desire to create more advanced and versatile interfaces between technology, the human body and the environment,” Gaharwar said. “The most exciting aspect of this research is its potential applications in robotics, prosthetics, wearable technology, sports and fitness, security systems and entertainment devices.”

E-skin technology, detailed in a study published by Advanced functional materials, was developed in the Gaharwar laboratory. Drs. Kaivalya Deo, Gaharwar’s former student and now a scientist at Axent Biosciences, and Shounak Roy, a former Fulbright Nehru doctoral student in Gaharwar’s lab, are lead authors of the paper.

Creating E-skin involves challenges related to developing sustainable materials that can both mimic the flexibility of human skin, contain bioelectric sensing capabilities, and utilize manufacturing techniques suitable for wearable or implantable.

“In the past, the stiffness of these systems was too high for our body tissues, preventing signal transduction and creating mechanical imbalance at the biotic-abiotic interface,” Deo said. “We introduced a ‘triple cross-linking’ strategy into the hydrogel-based system, which allowed us to address one of the key limitations in the field of flexible bioelectronics.”

The use of nanoengineered hydrogels addresses some of the challenging aspects of e-skin development during 3D printing due to the ability of hydrogels to decrease viscosity under shear stress when creating the e-skin, thus allowing for easier handling and handling. The team said this feature makes it easier to build complex electronic structures in 2D and 3D, a critical aspect of replicating the multifaceted nature of human skin.

The researchers also used an “atomic defect” in nanoassemblies of molybdenum disulfide, a material containing imperfections in its atomic structure that allow high electrical conductivity, and polydopamine nanoparticles to help e-skin adhere to tissue. damp.

“These specially designed molybdenum disulfide nanoparticles acted as cross-linkers to form the hydrogel and imparted electrical and thermal conductivity to the e-skin; we are the first to report the use of this as a key component,” Roy said. “The material’s ability to adhere to wet tissues is particularly crucial for potential healthcare applications where e-skin must conform and adhere to dynamic, wet biological surfaces.”

Other collaborators include researchers from the group of Dr. Limei Tian of the Department of Biomedical Engineering at Texas A&M and Dr. Amit Jaiswal of the Indian Institute of Technology, Mandi.