"When we used to make textiles, we never considered the relationship between the double-stranded thread and nature, and developed the technology entirely from a practical perspective. However, the structure of the DNA double helix has been used in textiles for thousands of years, and human beings are still using it extensively up to now, and probably won't change it in the future, and this has given us a sense of the wonders of the natural world and its mapping in the textile field.
Recently, the team published a paper in Advanced Materials titled "Ultrafast-Response/Recovery Flexible Piezoresistive Sensors with DNA-like Double Helix for Epidermal Pulse Monitoring. Piezoresistive Sensors with DNA-Like Double Helix Yarns for Epidermal Pulse Monitoring).
In textile, double helix yarns are very common and also one of the basic structures. During the research process, Jinlian Hu realized that the structure of double stranded yarns worked very well. Later, they realized that the structure is the same as DNA. In their research, they achieved two main goals: first, they solved the recovery lag of textile materials for pressure sensors; and second, they developed pressure sensors for use in scenarios such as pulse-taking in traditional Chinese medicine.
A "long story"
Zhang Yuanting, Chair Professor of Biomedical Engineering at the City University of Hong Kong, is a colleague of Hu's, and an expert in blood pressure measurement and cardiovascular medicine. experts. Earlier, he worked at the Chinese University of Hong Kong, and the two sides sometimes attended meetings together.
Now, Zhang Yuanting has a big center in Hong Kong Science and Technology Parks, where the government has allocated several hundred million dollars to develop real-time cardiovascular-related monitoring devices. The other side pulled in Hu Jinlian to work with them, during which the latter sent a student to find out what problem Zhang Yuanting's group was hoping to solve. Learning that they needed a pressure sensor to measure blood pressure, Hu and the student made several versions, including one that had a paper on the subject that had been published a few years earlier.
Coming from a background of studying textiles, she realized the performance of the sensor mainly by designing the fabric structure. Later, she found a yarn and tested different configurations such as single, double, and four strands, and found that two interwoven strands performed the best, so she used it for the pressure sensor.
This sensor has two main advantages: first, the pulse is constantly beating up and down when you take your pulse, and it does so frequently, which causes the material to go through a cycle of deformation-recovery-deformation, and there is almost no hysteresis in the sensor prepared with the two-stranded yarn, which indicates that it is very capable of recovery. In addition, since the strength of the pulse is not very strong, the response of the sensor must be controlled within the range of force so that it is more effective, otherwise the performance and hysteresis of the sensor will change. In summary, this sensor is accurate, lag-free, and repeatable when measuring pulse.
Students are incubating related companies
Hu Jinlian said this application is mainly related to the body, and in the future it is expected to be used in robotics. The biggest requirement for wearable devices is to fit with the skin or conform to the human physiology. First, it should be easy to deform, because the body are irregular. Secondly, it needs to be exceptionally soft. You know, there are a lot of sensors on our skin, and a slight mismatch can easily make people feel uncomfortable.
In the past, one might use a hard optoelectronic device placed on the skin and collect data for processing, which is certainly not compatible with the body's needs. Then came flexible devices, which are essentially bendable. But that still wasn't enough, and so came stretchable materials. Textiles can adapt to a variety of deformations, including stretching, bending, and shearing, making them an ideal type of material for developing wearable devices.
In terms of follow-up plans, a fund has been set up at City University of Hong Kong, and Jinlian Hu's students are setting up a company. However, they have only made a sensor, and more comprehensive research is needed if they are to make a truly applicable device. For example, reliable electrodes need to be added, signals need to be extracted and processed, and parameterization needs to be done before they are visible. Because the project is the City University of Hong Kong HK300 innovation project, does not allow teachers to do the main person in charge, so Hu Jinlian just as a consultant and shareholder, specifically students to operate.
"One-stop" research
It is reported that Hu Jinlian is a Hubei native, came to Hong Kong 28 years ago. After finishing her master's degree on the mainland, she also worked in the community, and was awarded the Sino-British Cooperative Technology Scholarship, which allowed her to study in the United Kingdom. After getting her doctorate, she returned to China to work, first at the Hong Kong Polytechnic University, and then at the City University of Hong Kong. Currently the team is about 30 people.
Studying textiles as a student didn't come from the usual "girls might love textiles more" reasons. On the contrary, she says that when she was an undergraduate, she really didn't have much of a feeling for textiles, and preferred science. When she was in college, the "Ten-Year Rebellion" had not long passed, and the conditions were relatively poor. Learning textile engineering, many machine structures she has never seen. And when listening to the class, she felt that these things are people stipulated, because then the main learning how to weave, learning the structure of the machine, as well as the design principles and functions of manufacturing, so she thought it was a bit of a waste of time.
Later, when she did her master's degree, she chose textile materials science because it was closer to science. At that time, textile material science was a relatively special specialty, and when she came to Donghua University for her master's degree (then called China Textile University), it just happened to have this specialty. In the textile program, she had not studied engineering, so it was difficult to understand and derive.
But for textile material science, she could read books on the subject to understand the connotations. Learning a theorem could introduce something else without studying those machines. Later, because Hu Jinlian was admitted from an outside school, the school transferred her to textile products, which is a specialty combining textile engineering and textile materials. After that, she went to England to study and continued her research in this area as well. After graduation, she joined the Hong Kong Polytechnic University, where she taught textile engineering at first, but almost all the research she did was in materials.
From fibers, to cloth, to clothing, and then she moved further into materials, and later started doing synthesis of polymers. In addition, the Hong Kong Polytechnic University has a textile department, so from textile materials, to clothing, to sales are her teaching and research areas. She said, "From the synthesis of polymer materials to the performance of the finished textile products, I did it 'one-stop', and this experience is very unique and not available to the general public."
At the same time, it also has to do with the business environment in Hong Kong. At that time, she wanted to make functional smart fabrics, a material that has a strong market in Hong Kong, and there are many related companies. After receiving funding from the company, she was able to go to the Hong Kong government to apply for big projects, which often go from material design, to synthetic processing, and then into textiles. Having done several rounds of large projects has made her particularly comfortable working with the company, and the company particularly likes her.
Hu Jinlian said, "I didn't think of myself as a female professor or having any disadvantages or advantages, I didn't think about that. Basically, I did what I had to do without being condescending. Most importantly, I know the research context up and down the line and can bring them together organically from start to finish."
For example, to develop a product, you first have to understand the requirements of the product. At this point, Hu Jinlian will be realistic to identify the problem, and then look for solutions. She said, "These solutions are not limited by textile or polymer materials, as long as I think I can solve the problem of learning, including nanotechnology and biomedical cutting-edge things, I am willing to learn."
Currently, she has 50 patents granted and more than 30 patents pending. In Hong Kong, she was one of the first teachers to apply for patents in 1994, when there was not much research activity in Hong Kong. As one of the earlier scholars, she was very active and did some pioneering work. For example, at that time, there were no teachers in the university to apply for patents, and there were no related supporting services. Later, thanks to her efforts, the university began to establish an intellectual property office, and even had a vice president in charge of it. She said, "I witnessed this process and was one of the first to get involved, as well as promoting the development of the Hong Kong Polytechnic University and the City University of Hong Kong in terms of patents."
Commercial returns are expected soon
Currently, Hu Jinlian owns a Center for Wearable Medical and Healthy Materials at the City University of Hong Kong, where her research interests include apparel materials and textile materials, among others. Specifically there are three directions: the first direction is Chinese medicine and energy therapy, including acupuncture and gua sha, electromagnetic light, etc.; the second direction is spider silk bionics and its applications, and the third direction is infantile materials especially clothing and biomaterials.
"Materials are our strength," she said, "and when doing energy and Chinese medicine therapies, it also starts with materials. For example, is it better to use a gua sha board with cow horn? Or is it better to use ceramics? With this we can also study the interaction between materials and organisms."
On industrial incubation, she said, "I've been here at the City University of Hong Kong for two years now, and the students in the group got three commercialization projects including an angel fund, and in addition to the funding from the City University of Hong Kong, we also got two projects funded by the Hong Kong Science and Technology Parks. In addition, I also have a project at the Hong Kong Polytechnic University, all these projects are under incubation and may have some effect and commercial returns immediately."
-End-
Supported by: Dayi
References:
1, Chen, J., Zhang, J., Hu, J., Luo, N., Sun, F., Venkatesan, H., ... & Zhang, Y. (2022). Ultrafast-Response/Recovery Flexible Piezoresistive Sensors with DNA-Like Double Helix Yarns for Epidermal Pulse Monitoring. Advanced Materials , 34(2), 2104313.