[instrument R & D] mobile phones can be bent like a film at random? B ultrasonic instrument can be affixed to the body to monitor the condition of the body in real-time? Can a sport suit worn on the body automatically generate electricity? Southeast University's research team and collaborators have made breakthroughs in the field of piezoelectricity in molecular materials, making the imaginations of these sci-fi films possible in the future.

  

Piezoelectricity is the property of a material that can produce electricity when it is squeezed or stretched, or when it is applied to the two section of the material. Materials with piezoelectric properties are also referred to as piezoelectric materials. People use quartz watches, medical B ultrasound, and even the "shake" function of mobile phones, are piezoelectric materials in real life applications.

At present, the piezoelectric material is mainly inorganic ceramic, but this material needs high temperature firing. It has the disadvantages of no film forming, poor flexibility, no environmental protection, no recycling, and it is difficult to carry out miniaturization applications. The molecular materials can well supplement these defects of inorganic ceramic materials, but the piezoelectric properties of the former are far less than those of the latter.

Today, the new molecular ferroelectric materials synthesized by the Southeast University team have reached the level of traditional piezoelectric ceramics for the first time in piezoelectric properties and have advantages in both molecular materials.

The research group responsible for the tour Yumeng Professor vividly explains the innovation team in the synthesis of. A piezoelectric material is like a sponge. The water squeezed out by a sponge is like an electric current. The principle of traditional piezoelectric material is equivalent to squeezing on both sides of the sponge, and our piezoelectric material is equivalent to light twist and bend the sponge, so that under a very small pressure can get a lot of electricity."

According to reports, since 1880, Curie brothers in quartz single crystal found piezoelectric effect, there has never been a case of molecular power generation materials can have such a large piezoelectric performance.

Of course, in the process of innovation will also encounter difficulties.

You Yumeng said that in the course of nearly 4 years of research and development process, the team of several doctors only three or four days off the summer vacation, they returned to the laboratory for research. In addition to the challenges of design, synthesis, testing, etc., the biggest difficulty is how to make the new direction of the development of molecular ferroelectric materials to be recognized by inorganic materials researchers. "Because they are mature in their study of inorganic materials, they already have a set of standards of their own, and we hope that our new materials will meet their standards and be recognized by them."

Sun Yueming, executive vice president of Southeast University Research Institute evaluation said, this study provided a team at the Southeast University in the research field of molecular ferroelectric lead position, at the same time, small molecular ferroelectric materials have very broad prospects.

Prof Yu said that new molecular ferroelectrics could be used to scale large medical devices in the future. For example, the blood pressure meter, B ultrasound machine and other "large equipment" to reduce and integrated in the daily clothing, made "wearable" medical equipment. In addition, the new molecular ferroelectric materials can also play a role in human-computer interaction technology, micro electro mechanical systems, aerospace and other fields.

However, he also said that it may take more than 10 years for the laboratory to be truly extended to applications, not only in terms of technology, but also in capital operation.

"A major breakthrough in the field of molecular materials in piezoelectric on the breakthrough, just like the first Crossopterygii ashore, it put our research field of piezoelectric materials from aquatic to terrestrial, what we see is a vast new world without. There are many opportunities and challenges on this continent." You Yumeng said, "we also hope that the research has more research into the molecular piezoelectric material, we put together the molecules of piezoelectric materials to expand and bring more convenience to the people".

The research team of Southeast University also cooperated with the research team of Nanjing University, Peking University, University of Washington and other universities. Research results were published online in July 21, 2017 by the world's top academic magazine, science. This paper is also an important achievement of the Key Laboratory of molecular ferroelectric science and applications in Jiangsu province.