Ying-Chih Lai, who co-authored the paper, said modern vehicles are typically equipped with cameras that help monitor their surroundings, but these cameras can be unreliable in low light, darkness, and poor weather conditions.
Alternatively, light detection and ranging systems (LiDAR) use lasers to help map the surroundings, but they’re also less reliable in poor weather. LiDAR systems are expensive, too, and not likely to see widespread use on typical vehicles.
The other problem with both of these safety strategies, said Lai, is that they need continuous power input. “The SNC-TENG, as a self-powered active sensor, does not require any power from the vehicle,” he said. “It can actively perceive the surrounding objects with no need of continuous electricity.”
Instead of drawing power from the car’s battery, the sensor is powered by electrostatic induction, which means it gets its electrical charge from the electrical fields of nearby objects. Nanosheets made from a titanium-based 2D material called MXene help increase the device’s charge-trapping capacity, while a conductive sponge increases the number of particles that can carry an electric charge.
This design not only powers the device, it also gives it the ability to detect objects at ultra-long distances of up to two meters. The nanogenerator can even detect very slight movement of around 1 mm.
The researchers tested their device on a real vehicle and found that it could provide accurate blind spot detection as well as parking lot monitoring and theft and vandalism protection.
For the latter, it “can detect the approaching persons via the electrostatic induction with no need for physical contact,” Lai said. “Then, the generated electrical signals can activate the onboard surveillance camera to monitor the surrounding circumstances.”
If the approaching person touches the sensor, Lai said, it will trigger an alarm. Ultimately, the researchers envision a system that will send an immediate warning to the owner’s mobile phone when the device senses a theft attempt.
Similarly, the researchers said their device can be used to monitor nearby cars while the vehicle is parked. When the sensor detects a vehicle that’s too close, it will trigger a surveillance recording so if there’s a parking lot collision, the offending driver can be held accountable.
In their paper, the researchers said their sensor is not only highly sensitive and energy-smart but also cheaper and easier to make than many conventional sensors. This is an important point since the energy requirements of traditional sensors contribute to increased vehicle manufacturing costs and environmental pollution.
Self-powered sensors, they said, could help offset both the financial and environmental costs of modern vehicles, making them more carbon-friendly. A less expensive, simpler sensor could also help “accelerate the development of smart and secure vehicles,” they wrote, and “promote advances in a wide range of noncontact sensing technologies.”
Reference: Minyi Xu, Ying-Chih Lai, et al., MXene-Composite-Enabled Ultra-long-Distance Detection and Highly Sensitive Self-Powered Noncontact Triboelectric Sensors and Their Applications in Intelligent Vehicle Perception, Advanced Functional Materials (2023). DOI: 10.1002/adfm.202306381
Feature image credit: Raban Haaijk on Unsplash
This article was updated on October 19, 2023 to include reference to contributions made by researchers at the National Chung Hsing University in Taichung.