Researchers at The Hong Kong Polytechnic University (PolyU) have created a singular variety of nanotechnology sensors that can be sprayed on flat or curved surfaces, like train tracks and or airplane wings.
.jpg)
The sprayed sensors can be networked, to provide deep, real-time data on the status of the structure below.
The new sensing technological is a network with nanocomposite sensors and an ultrasound actuator. The technology can actively sense the condition of the structure it is attached to, quickly and precisely indicating if there is any damage.
Standard ultrasound sensors, like those made of lead zirconate titanate (PZT), are generally limited by the factors associated with their cost and physical properties. These sensors are rigid, as well as relatively heavy and bulky – which can affect the performance of a structure to which these sensors are affixed.
To acquire structural data, the new PolyU sensor uses an ultrasound actuator to produce guided ultrasonic waves (GUWs). Nanocomposite sensors then receive and evaluate the waves. If damage, like a crack exists in the structure, distribution of GUWs will be interrupted by the damage, resulting in distinctive wave scattering being captured by the sensor network.
Using the wave scattering pattern, the damage can be recognized via a comprehensive system created by the team. Every sensor is linked to a network via a wire printed on the structure. By assessing and contrasting the electrical signals transformed by electric resistivity, the network can find the defect in a structure, along with convert the signals into 3D models.
While current ultrasound sensors cost more than $10 each and weigh several grams, this new strain of nanotechnology sensor costs just $0.50 to make and weighs 0.04 grams. As a result, more sensors can be used on one structure, producing more data for evaluation, with less weight added onto the structure.
Furthermore, the new sensor has superb flexibility and can conform to curved structure surfaces, which allows for a wide variety of engineering applications. The technology can also be sprayed onto the surface of a moving structure to deliver the structural data in real-time.
The Researchers behind the new kind of sensor said their breakthrough is a game changer for sensor technology.
This nanocomposite sensor has blazed a trail for implementing in-situ sensing for vibration, or ultrasonic wave-based structural health monitoring, by striking a balance between 'sensing cost', i.e. the cost of sensors, and 'sensing effectiveness', the quantity of data acquired by the sensors.
Su Zhongqing, Professor, Department of Mechanical Engineering, The Hong Kong Polytechnic University
Created from a hybrid of carbon black (CB), graphene, conductive nano-scale particles and polyvinylidene fluoride (PVDF), the novel detector can be readily customized to several sizes for various engineering applications.
The PolyU Researchers said the key to the high sensitivity of the sensor is based on its optimized nanostructure, which gives it the ability to identify the dramatic shifts in piezoresistivity caused by ultrasound waves. The team said they tested many 'nanofillers' to be able to optimize the conductivity of their nanocomposite.
The sensor created by the team can gauge an ultrasound signal from static to up to 900 kHz, a response frequency 400 times greater than other nanocomposite sensors that are reportedly available, the Researchers said. That degree of sensitivity allows for the detection of cracks as small as 1 to 2 millimeters. While typical ultrasound sensor can evaluate a broader range of ultrasound waves when as opposed to those created by the team, they are limited by the cost and physical proportions.
Due to its light weight, the novel nanocomposite sensors can be applied to moving structures like trains and airplanes. That will help to pave the way for real-time monitoring of these structures in future, enhancing safety of the engineering assets and retrofit the traditional system maintenance philosophy.
Su Zhongqing, Professor, Department of Mechanical Engineering, The Hong Kong Polytechnic University
Source:
PolyU develops sprayable sensing network technology
Image Credit:
Shutterstock.com/ Langunculus
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.