New Wearable Brain-Computer Interface

A micro-scale brain sensor on a finger

A micro-scale brain sensor on a finger. Credit: W. Hong Yeo.

Micro-brain sensors placed between hair strands overcome traditional brain sensor limitations.

Georgia Tech researchers have developed an almost imperceptible microstructure brain sensor to be inserted into the minuscule spaces between hair follicles and slightly under the skin. The sensor offers high-fidelity signals and makes the continuous use of brain-computer interfaces (BCI) in everyday life possible.

BCIs create a direct communication pathway between the brain's electrical activity and external devices such as electroencephalography devices, computers, robotic limbs, and other brain monitoring devices. Brain signals are commonly captured non-invasively with electrodes mounted on the surface of the human scalp using conductive electrode gel for optimum impedance and data quality. More invasive signal capture methods such as brain implants are possible, but this research seeks to create sensors that are both easily placed and reliably manufactured. 

Hong Yeo, the Harris Saunders Jr. Professor in the George W. Woodruff School of Mechanical Engineering, combined the latest microneedle technology with his deep expertise in wearable sensor technology that may allow stable brain signal detection over long periods and easy insertion of a new painless, wearable microneedle BCI wireless sensor that fits between hair follicles. The skin placement and extremely small size of this new wireless brain interface could offer a variety of benefits over traditional gel or dry electrodes.

“I started this research because my main goal is to develop new sensor technology to support healthcare and I had previous experience with brain-computer interfaces and flexible scalp electronics,” said Yeo, who is also a faculty member in Georgia Tech’s Institute for People and Technology. “I knew we needed better BCI sensor technology and discovered that if we can slightly penetrate the skin and avoid hair by miniaturizing the sensor, we can dramatically increase the signal quality by getting closer to the source of the signals and reduce unwanted noise.”

Today’s BCI systems consist of bulky electronics and rigid sensors that prevent the interfaces from being useful while the user is in motion during regular activities. Yeo and colleagues constructed a micro-scale sensor for neural signal capture that can be easily worn during daily activities, unlocking new potential for BCI devices. His technology uses conductive polymer microneedles to capture electrical signals and conveys those signals along flexible polyimide/copper wires — all of which are packaged in a space of less than 1  millimeter.

A study of six people using the device to control an augmented reality (AR) video call found that high-fidelity neural signal capture persisted for up to 12 hours with very low electrical resistance at the contact between skin and sensor. Participants could stand, walk, and run for most of the daytime hours while the brain-computer interface successfully recorded and classified neural signals indicating which visual stimulus the user focused on with 96.4% accuracy. During the testing, participants could look up phone contacts and initiate and accept AR video calls hands-free as this new micro-sized brain sensor was picking up visual stimuli — all the while giving the user complete freedom of movement.  

According to Yeo, the results suggest that this wearable BCI system may allow for practical and continuous interface activity, potentially leading to everyday use of machine-human integrative technology.

“I firmly believe in the power of collaboration, as many of today’s challenges are too complex for any one individual to solve,” said Yeo. “Therefore, I would like to express my gratitude to all the researchers in my group and the amazing collaborators who made this work possible. I will continue collaborating with the team to enhance BCI technology for rehabilitation and prosthetics.”

 

Note: Hodam Kim (postdoctoral research fellow), Ju Hyeon Kim (visiting Ph.D. student from Inha University – South Korea), and Yoon Jae Lee (Ph.D. student) also played a major role in developing this technology.

Funding: National Science Foundation NRT (Research Traineeship program in the Sustainable Development of Smart Medical Devices), WISH Center (Institute for Matter and Systems), and partial research support from several South Korean programs and grants.

PNAS article publication (April 7, 2025, Vol. 122, No. 15): https://www.pnas.org/doi/10.1073/pnas.2419304122

A micro-scale brain sensor placed between hair follicles.

A micro-scale brain sensor placed between hair follicles. Credit: W. Hong Yeo.

News Contact

Walter Rich, Research Communications

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Celebrate STEAM | Atlanta Science Festival Launch at Georgia Tech

Members of the Georgia Tech community are excited to welcome the community back to campus for the kickoff event of the 12th annual Atlanta Science Festival. Formerly known as Georgia Tech Science and Engineering Day, Celebrate STEAM will feature hands on activities for participants of all ages. Whether your interests lie in robotics, brains, biology, space, art, nanotechnology, paper, computer science, wearables, bioengineering, chemical engineering, or systems engineering, we have something for everyone.

Georgia Tech’s Executive Vice President for Research Search: Finalist 1 Seminar

Each candidate’s bio and curriculum vitae, along with further details, will be accessible through the EVPR search site two business days ahead of each visit. Georgia Tech credentials are required to access all materials. Information is being made available in this manner to protect the confidentiality of the finalists.

Finalists Chosen in Georgia Tech’s Executive Vice President for Research Search

Historical sign depicting information about Tech Tower

Georgia Tech’s Executive Vice President for Research (EVPR) search committee has selected three finalists. Each candidate will visit campus and present a seminar sharing their broad vision for the Institute's research enterprise. 

The seminars are open to all faculty, students, and staff across the campus community. Interested individuals can attend in person or register to participate via Zoom (pre-registration is required).    

All seminars will take place at 11 a.m. on the following dates:  

  • Candidate 1: Monday, January 13, Scholars Event Theater, Price Gilbert 1280 (register for webinar)  
  • Candidate 2: RESCHEDULED to Wednesday, January 29, Scholars Event Theater, Price Gilbert 1280 (register for webinar)
  • Candidate 3: Monday, January 27, Scholars Event Theater, Price Gilbert 1280 (register for webinar)  

Each candidate’s bio and curriculum vitae, along with further details, will be accessible through the EVPR search site 48 hours prior to each visit. Georgia Tech credentials are required to access all materials. Information is being made available in this manner to protect the confidentiality of the finalists. Following each candidate’s visit, the campus community is invited to share their comments via a survey that will be posted on the candidate’s webpage.   

The search committee is chaired by Susan Lozier, dean of the College of Sciences. Search committee members include a mix of faculty and staff representing colleges and units across campus. Georgia Tech has retained the services of the executive search firm WittKieffer for the search.  

News Contact

Shelley Wunder-Smith | shelley.wunder-smith@research.gatech.edu
Director of Research Communications
 

Intelligent XR for Adaptive Task Guidance in Future Factories

Mohsen Moghaddam
Gary C. Butler Family Associate Professor
H. Milton Stewart School of Industrial and Systems Engineering
George W. Woodruff School of Mechanical Engineering
Georgia Institute of Technology

Monday, April 7
12:00 - 1:00 PM Eastern Time
Location: Callaway/GTMI bldg.,
Room 114

Lunch provided for in-person attendees on a first come first serve basis.