Research & Innovation

Ear on Health: Stevens Research Integrates Electronics with the Body

Imagine a tooth with its own sensor that could help detect decay or disease and warn dentists and doctors. Imagine a replacement ear, formed on a 3D printer and grown in a lab, with built-in electronics that detect sound and carry it to the brain.

Once something out of a science-fiction novel, these advancements are now moving closer to reality in the laboratory of Manu Mannoor, an assistant professor of mechanical engineering at Stevens.

Mannoor, with backgrounds in mechanical engineering, biomedical engineering and electronic communications, combines the three fields in innovative research toward what he calls “bionic systems” – engineered devices designed to mimic or enhance human organs, tissues and functions.

He believes the research could lead to custom-formed replacement body parts for those who have been injured or disfigured by accidents, and could also lead to the development of organs that one day allow us to exceed normal human capabilities.

“My research is an effort to integrate all three of these disciplines, and the way I do it is through materials science,” he says. “This work blurs the boundaries between them while advancing all three disciplines.”

The research is an outgrowth and continuation of work Mannoor was involved in prior to joining Stevens. After completing undergraduate studies in electronics and communication at the University of Calicut in his native India, he earned master’s degrees in biomedical engineering from New Jersey Institute of Technology and mechanical and aerospace engineering from Princeton University. He later earned his Ph.D. in mechanical and aerospace engineering from Princeton, where he began the bionic systems work as a postdoctoral fellow. 

Smart teeth, improved auditory function

Mannoor’s ultimate goal is to create a device that is fully integrated with the body. His bionic tooth is a good example: like a tattoo, it is not merely meant to be worn, but rather becomes part of the body. The lab-developed tooth sensor is a tiny wireless communication device fashioned from graphene, pliable enough to mold to contours of a tooth and bond with natural enamel; the sensor is formed on a super-thin layer of silk, which then dissolves once the sensor is applied. The sensor carries no electrical power, but contains components that can connect wirelessly with a powered device outside the body, allowing it to transfer data.

Depending on how the sensor is programmed, it can flag signs of tooth decay or gum disease, and even potentially provide early warnings of stomach cancer, ulcers or other illnesses by continuously monitoring breath and saliva for specific bacteria.

The bionic ear is another example of merging electronics and tissue to improve health. To build his ear, Mannoor three-dimensionally prints silver particles that will form an electronic coil antenna with a scaffold composed of a mixture of cells and man-made materials. The framework of the ear is printed layer-by-layer, then nurtured in a bath of cartilage cells and nutrients to help it grow. This printing technique allows the ear to be built gradually, with all electronic components completely integrated as it's constructed. Mannoor says this method has proven better at forming highly complex, contoured structures such as ears than the traditional tissue replication and reconstruction techniques currently used in plastic surgery. 

In a completed bionic ear, the coil antenna connects to wires that could be attached, like a hearing aid, directly to a patient's nervous system. 

Although more development work and testing is required before the ear could be implanted in a patient, Mannoor says his antenna can be designed to pick up sounds beyond the ranges of normal human hearing, thus not only restoring hearing but enhancing it. There may also be military applications for the technology, and he hopes the techniques he is developing will also one day be used to create other body parts such as replacement joints that physicians can monitor and use to prevent injuries from recurring.