Imagine wearing a small patch that can instantly warn you if you are exposed to dangerous gases or contaminated water.
Instead of sending an alert to your phone that you might not notice right away, the patch vibrates against your skin, giving you an immediate warning to move away from danger.
Researchers at North Carolina State University have developed just such a device. Their new wearable technology can detect several environmental hazards and alert the wearer through different vibration patterns.
The team has also adapted the same technology into an electronic “skin,” or e-skin, that allows robots to sense hazards and avoid them automatically.
The research was published in the journal Device.
Many environmental sensors already exist, but they usually send notifications to a smartphone or computer.
While useful, these alerts can easily be missed if the user is not looking at their device. The research team wanted to create something that delivers warnings instantly through the sense of touch.
The wearable patch is small and lightweight, measuring slightly smaller than a driver’s license. Inside the patch is a tiny computer that controls the system, a small battery, several sensors, and a miniature motor that creates vibrations against the skin.
The outside of the patch is covered with thin solar cells that collect energy from sunlight while the device is being worn. This extra power helps extend the battery life.
The patch is designed to monitor six different environmental hazards, including dangerous gases and heavy metals in water. As soon as one of these hazards is detected, the patch immediately begins vibrating.
The researchers wanted the warning to be easy to notice, so they carefully designed the area where the vibrating motor touches the skin. They created tiny raised patterns between the motor and the skin, allowing them to control how the vibrations feel. By adjusting the size and spacing of these small bumps, they produced vibrations that are much more noticeable than a simple buzzing motor.
The device can also communicate what type of hazard it has detected. Instead of using the same vibration every time, it produces a unique vibration pattern for each hazard. After learning the patterns, users can quickly recognize whether they are dealing with contaminated water, dangerous gases, or another environmental risk without needing to check a screen.
In early testing, the patch successfully detected hazardous substances and immediately delivered the correct vibration warning. Thanks to its low power use and solar energy harvesting, the device can operate for about 24 hours before needing to be recharged.
While developing the wearable patch, the researchers realized the same idea could help robots stay safe. This led them to create an electronic skin that can be attached to robotic machines.
The robotic e-skin places the sensor patch on top of a special material called a piezoelectric layer. When the patch vibrates after detecting a hazard, the piezoelectric material converts those vibrations into electrical signals. The robot can then recognize the signal and respond automatically.
In proof-of-concept tests, four-legged robots fitted with the e-skin were able to detect hazards in their surroundings and change direction to avoid dangerous areas without human assistance.
One advantage of the new technology is that it is highly flexible. Most of the device is built using readily available electronic components, making it easier to manufacture and improve in the future. The sensor system is also modular, meaning different sensors can be added or removed depending on where the device will be used.
The researchers believe the technology could eventually be useful for factory workers, emergency responders, environmental inspectors, and others who regularly work in hazardous conditions.
It could also help create safer robots that can explore dangerous locations while protecting both themselves and the people working nearby.
