The latest nanocomposite sensor can be directly sp

It is reported that the research team of the Hong Kong Polytechnic University has recently developed a new nanocomposite sensor, which can be directly sprayed on flat or curved engineering structures, such as train tracks and aircraft structures. The sprayed sensor can further form a sensor network to provide real-time and rich structural health information for the monitored structure

the nanocomposite sensor was developed by Professor Su Zhongqing and Professor Zhou Limin of the Department of mechanical engineering of PolyU and the team led by them. It is made of innovative spraying technology, which makes the sensor installation process faster and more efficient than the traditional method. This new technology also makes the sensor suitable for a variety of engineering structure surfaces, improving its flexibility

new technology saves cost and improves sensitivity

nanocomposite sensors are made of carbon black, two-dimensional graphene, conductive nanoparticles and polyvinylidene fluoride. They can be easily and flexibly made into different sizes according to the needs of various engineering applications

the new nanocomposite sensor can sensitively detect structural changes due to the optimization of the actually simple nanostructure of the mixture. It can recognize the feedback of nanocomposites to different Piezoresistances

in this new technology, each sensor is connected to the network through wires printed on the structure. By analyzing and comparing the electrical signals converted from resistivity, defects in the structure can be found, and the signals can be converted into three-dimensional images

light weight and low cost

this sensor is extremely light weight and low manufacturing cost. It can be widely used to detect problems hidden in the structure, which will help to create a new era of structural health monitoring based on ultrasound

the fracture of the sample is always broken on both sides

it contains a sensor network, which is composed of multiple nanocomposite sensors and an ultrasonic transducer. It can actively detect the health of the structure installed with the sensor network, and quickly and accurately show whether the structure is damaged

the sensor will receive and measure the ultrasonic guided wave sent by the ultrasonic transducer. If the structure is damaged, such as cracks, the propagation of the ultrasonic guided wave will be disturbed by the damaged place, so the unique wave scattering phenomenon will appear and be recorded by the sensing network. The integrated system developed by the team can accurately detect and quantify structural damage based on the scattering of ultrasonic guided waves

it is reported that the traditional ultrasonic sensor is made of piezoelectric materials, which costs more than ten dollars and weighs several grams; This new year's sales revenue reached 5. The cost of the first generation nanocomposite sensor was only 0.5 US dollars, weighing 0.04 grams

therefore, a structure can use more sensors at the same time to obtain more information for analysis, without bringing significant load to the structure

it has good flexibility and can be applied to curved structural surfaces

in addition, this nanocomposite sensor has excellent flexibility and is suitable for curved structural surfaces. It can be widely used in various engineering structures. Even on the surface of mobile structures, it can also be installed by spraying to transmit structural health information in real time

wider response frequency

this nanocomposite sensor can measure small amplitude ultrasonic signals from static to 900 kHz. This technology can collect scattered waves in the ultrasonic system, so as to detect cracks as small as 1-2 mm in most engineering materials. The response frequency is more than 400 times higher than that of the existing nanocomposite sensors (according to existing reports in international journals)

although the measurable ultrasonic range of the traditional ultrasonic sensor is wider than the response frequency of this nanocomposite sensor, the weight and cost of the traditional sensor are high, so it is difficult to form a large sensor network, so it can only bring limited data. In many practical engineering applications, especially for aerospace structures, there are great restrictions on their use

this new research has recently been published in top journals in its field, including ultrasonics, carbon, smart materials and structures, etc