Application of the inertial switch in sports to immediately detect possible brain injuries. Credit: Scientific Reports (2025). DOI: 10.1038/s41598-025-21637-8
A tiny sensor that detects hazardous head impacts the instant they occur could reshape safety monitoring in sports, transportation and other high-risk settings.
The device, developed by researchers at KAUST, acts like a safety switch that activates in response to sudden acceleration, sensing forces from any direction and gauging their severity in real time. The work is published in the journal Scientific Reports.
Roughly the size of a small fingernail, the sensor can be attached to football helmets, ski goggles, industrial hard hats or children's headbands. Drawing no power in its normal standby state, it switches on only when a shock closes the internal electrical circuit through mechanical contact between the movable and fixed structures. This means the sensor can operate for long periods without draining the battery or requiring routine upkeep.
"It's like a seatbelt for the brain," says Yousef Algoos, an electromechanical engineer who built the device as a Ph.D. student in the KAUST Robotics, Intelligent Systems, and Control Group led by Eric Feron. Algoos co-led the study together with Mohammad Younis from the State University of New York at Binghamton, United States.
2D omnidirectional inertial switch with multiple thresholds: (a) structural sketch and close-up views (b and c) of the of the first and second switches from different angles. Credit: Scientific Reports (2025). DOI: 10.1038/s41598-025-21637-8
How the sensor works and its advantages
"By combining omnidirectional precision, multi-threshold capability and passive operation, this innovation paves the way for next-generation wearable safety systems for concussion detection and impact monitoring in sports, transportation and daily life," Algoos says. "There is no sensor on the market that offers this combination of features," he adds.
The project began in response to a personal loss. In 2018, Algoos's brother Abdullah died following a car accident that led to head trauma and internal bleeding that doctors were slow to diagnose. "That experience opened my eyes to the life-saving importance of early smart detection tools on the spot," Algoos says.
Existing head-impact monitors are used only in limited settings, in part because most rely on accelerometers that must be powered continuously. That constant activity drains batteries, requires bulky housings and limits the technology largely to elite sports or research environments.
Testing, validation and future applications
The KAUST sensor takes a different approach. Rather than tracking movement nonstop, it stays dormant until a sharp jolt pushes a suspended mass inside the chip into contact with one of several concentric electrodes. Each contact corresponds to a different acceleration threshold, allowing the device to distinguish minor bumps from more dangerous blows without software, power-hungry circuitry or continuous monitoring.
To validate the design, the team subjected the chip to a series of controlled laboratory tests. Using a drop-table apparatus, they delivered shocks from multiple directions and found that the sensor consistently triggered at levels associated with mild and severe head trauma with 360-degree accuracy.
With those results in hand, the researchers are preparing for the next stage: mounting the sensors on crash-test dummies to evaluate how they respond during complex, whole-body impacts.
Although still a prototype, Algoos says the technology could eventually "trigger an immediate alert through a mobile app, an audible signal, or a wireless notification to caregivers, coaches, or first responders, depending on the final product design."
With a patent already filed, "we are now exploring commercialization pathways with potential partners," he adds.
Publication details
Yousef Algoos et al, A 2D omnidirectional inertial switch with multiple thresholds, Scientific Reports (2025). DOI: 10.1038/s41598-025-21637-8
Provided by King Abdullah University of Science and Technology
