Prof. Min Qiu's Team Wins Provincial Natural Science Award

22, 2022

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At the Provincial Science and Technology Innovation Conference held recently, in addition to the 2021 Zhejiang Science and Technology Award, a number of awards such as the 2021 Zhejiang Natural Science Award, the Technology Invention Award, and the Science and Technology Progress Award were announced. The work, "micro-nano-scale photothermal regulation and application" jointly completed by Min Qiu, Qiang Li, Ding Zhao, and Zhichao Ruan won the first prize of the 2021 Zhejiang Provincial Natural Science Award.

As we all know, light and heat are the two most common forms of energy in nature, and they can be transformed into each other. For example, the sun is a black body with a high temperature of 5500 degrees. The heat radiated by it is the sunlight we perceive, and when we absorb sunlight under the sun, we will feel heat again. "Micro- and nano-scale photothermal regulation" is to study the mutual conversion of light and heat generated by the interaction between light and micro- and nano-scale structures. Light-to-heat conversion is light absorption, and heat-to-light conversion is heat radiation.

Different from the traditional macroscopic material system, the structure at the micro-nano scale greatly changes the interaction between light and matter, resulting in a series of new mechanisms, new phenomena and new applications. The research of Qiu’s team is based on this. As early as in 2010, they designed and realized the efficient absorption of metal micro-nano structures in the optical band, becoming a pioneer in the field of micro-nano-scale optical absorption. After that, they continued to cultivate in the two directions of "light absorption" and "heat radiation", and achieved a series of important results.

In terms of light absorption, the research team realized the motion of light-induced objects in a vacuum environment for the first time. This research got rid of the dependence of traditional light drive on liquid environment, and opened up the subdivision field of light drive in non-liquid environment. The research results appeared on the cover of Physical Review Letters and earned the editor's paper of recommendation. The team also developed a differential device for analog computing, which is the first optical analog computing device to report sub-wavelength thickness in the world.

In terms of thermal radiation, the research team used the micro-nano photonic structure composite phase change material to amplify the change of thermal radiation through the local enhancement of an optical field, and successfully broke through the bottleneck of thermal radiation regulation, that is, the Stefan-Boltzmann law. Specifically, at room temperature, if radiation intensity needs to be doubled, the target temperature needs to be raised by about 60 degrees. Using the innovative material structure system of the research team, the target temperature change can be achieved by less than 10 degrees.

Based on micro- and nano-scale photothermal regulation, the research team has also developed thermal management fabrics with multiple functions such as heat preservation, heat dissipation, and power generation. This is equivalent to a "clothing" that only needs to be flipped on the "front and back" to switch the two modes of heat dissipation and heat preservation like an indoor air conditioner, and this "clothing" can also be used for thermal power generation, a wearable electronic device that can be worn. This process can also be applied to thermal management of buildings, infrared camouflage, and other applications.

The charm of basic scientific research is that once a breakthrough is achieved at the theoretical level, it is likely to open up a new world. Qiu said that although their research on micro- and nano-scale photothermal regulation and application has continued for 15 years, more than 80 papers have been published, and solutions have been proposed for the basic problems from light absorption to thermal radiation, "but currently what we have seen is only the 'tip of the iceberg'. Next, we will continue to explore the mechanism of light-matter interaction at the micro- and nano-scale, and accelerate the promotion of new technologies such as photothermal nanodrives out of the laboratory and into the market, contributing to economic and social development at the local and national level.”