Dr. Zhenan Bao, The K.K. Lee Professor
The Department of Chemical Engineering
Stanford University

From electronic skin to NeuroString

Abstract:  Human skin is a remarkable interface that combines mechanical compliance with a rich array of sensory functions, enabling continuous perception of the physical and chemical environment. Inspired by these capabilities, we have developed materials and device platforms that impart skin-like properties to electronics, progressing from electronic skin (e-skin) for robotics and wearable sensing toward soft bioelectronic interfaces capable of communicating with the nervous system and monitoring physiology deep inside the body.
A central challenge is to create electronic materials that simultaneously provide high performance, mechanical softness, stretchability, and intimate contact with biological tissues. We have developed molecular and materials design strategies for intrinsically stretchable semiconductors, conductors, dielectric materials, and sensors, and integrated them into mechanically compliant electronic systems. These advances have enabled e-skin platforms capable of detecting pressure, strain, temperature, and chemical signals while conforming to dynamic surfaces. For robotics, such multimodal sensing can provide information that vision alone cannot capture, including contact, force, texture, and slip, creating opportunities for more dexterous manipulation and physical intelligence.
We are extending these principles from two-dimensional skin-like electronics to three-dimensional interfaces with the body through NeuroString, a soft, flexible, fiber-shaped bioelectronic platform. By rolling highly integrated two-dimensional sensor arrays into a small-diameter fiber, NeuroString combines the mechanical advantages of a soft thread with high-density, multimodal sensing. The platform can incorporate electrophysiological recording and stimulation together with electrochemical and physical sensors for neurotransmitters, hormones, pH, pressure, and other physiological signals. Its small size and tissue-like mechanics enable intimate interfaces with organs and neural tissues while minimizing mechanical mismatch and motion artifacts.
These developments illustrate a broader evolution of electronic skin: from mimicking the sensory functions of human skin, to providing robots with a sense of touch, to creating bidirectional interfaces that interrogate communication between the brain and body. Ultimately, integrating soft materials, multimodal sensing, high-density electronics, and artificial intelligence may enable a new generation of systems that seamlessly connect the physical, biological, and digital worlds.

Bio:  Zhenan Bao is the K.K. Lee Professor of Chemical Engineering at Stanford University and, by courtesy, Professor of Chemistry, Materials Science and Engineering, and Bioengineering. She directs the Stanford Wearable Electronics Initiative (eWEAR) and served as Chair of the Department of Chemical Engineering from 2018 to 2022 and in 2025.

Prior to joining Stanford in 2004, Professor Bao was a Distinguished Member of Technical Staff at Bell Labs, Lucent Technologies (1995–2004). She received her Ph.D. in Chemistry from the University of Chicago in 1995.

Professor Bao is a member of the National Academy of Sciences, the National Academy of Engineering, the American Academy of Arts and Sciences, and the National Academy of Inventors, and is a foreign member of the Chinese Academy of Sciences. She is widely recognized for her work on artificial electronic skin, which is enabling a new generation of skin-like electronics for restoring the sense of touch in neuroprosthetics, advancing human-friendly robotics, enhancing human–machine interfaces, and enabling seamless health-monitoring devices. Nature has named her a “Master of Materials.”

Her honors include the VinFuture Prize for Female Innovators (2022), the ACS Chemistry of Materials Award (2022), the Gibbs Medal (2020), the Wilhelm Exner Medal (2018), and the L’Oréal-UNESCO For Women in Science Award (2017).

Professor Bao is a co-founder of two start-ups, which have developed materials used in commercial smartphones and FDA-approved blood pressure monitors used in hospitals. In addition, research from her group has been licensed as foundational technology for multiple startups founded by her students.