Westlake News WETALK

Hongyu Chen: Doing ’Useless' Research Can Push a Field Forward

20, 2022

Email: zhangchi@westlake.edu.cn
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The Connecting Great Minds series of seminars aims to share the latest achievements in basic scientific research and original technological innovation in the frontier fields of science with our Westlake community.

On April 16, five scholars from Westlake University shared their thoughts during the sixth session of this event. Let’s take a look at the research of Prof. Hongyu Chen, a principal investigator with the Nanosynthesis Laboratory in the School of Science at Westlake University.

After Chen and his research team assembled magnetic nanoparticles into a string, they turned it into the world's smallest stirrer, stirring tiny droplets under the action of a magnetic field. "I don't know what it can do. Maybe it can make another nanosaw,”said Chen. “I'm looking at ways to create nanotopography.”

Chen’s research seems a bit unconventional: He always characterizes it as "useless" but "meaningful". Nanotechnology is a hot research field in the new century, and with a 1:10⁻⁹ unit of measurement, it makes it difficult to imagine the sizes we are talking about here. Chen uses an analogy to help us get our minds around the dimensions. If a model of the globe with a diameter of about 1 meter is enlarged to the size of the entire earth, then a die is one nanometer wide, and an apple is 10 nanometers wide. So, research into nanosynthesis methods is like a giant creature standing outside the earth, reaching into the microscopic world.

"Since you can't manipulate it directly, you have to use some basic physical and chemical methods to make it what you want it to become. Our job is to develop more of this 'magic'," said Chen.

By casting this magic, making nanoscale particles, interesting changes occur, such as new physical properties. In his presentation, Chen displayed an ancient Roman cup dating from the fourth century AD emitting red light throughout the body, which is the response of gold nanoparticles to light. New physical properties have spawned new application technologies, such as graphene coatings, which are widely used in the field of materials science to improve electrical conductivity, or fluorescent quantum dots for tracking and detection in the field of life medicine. Generally speaking, the nanomaterials currently used are all simple shapes such as nanospheres and nanowires.

What Chen thinks more interesting is the nanoscale machine: "When the particles are made small, they can enter cells, but to make a machine, this is a completely different application. It is much more complicated than the original, and the magic of synthesis has to become very powerful." Moving from single nanostructures to different control nanostructures involves deformation and assembly, which requires new chemical and physical control methods. This is exactly what Chen has been doing all along—developing new synthetic methods, discovering the mechanisms behind them, and applying these tools to expand novel nanostructures and explore new applications.

This is a basic synthesis, and if a new structure cannot be made, it is difficult to be used for exploration and application. The processing method of materials, just like the development of chemistry or carpentry, makes it difficult to make delicate and complex structures with only a few tools. Basic science needs to be studied with a serious mind, not only to make the existing pots, bowls and swords more refined and more easy to use, but more importantly, to accumulate methods and tools, that is, synthetic control, to lay the foundation for future applications.

When Einstein first proposed quantum theory in 1905, no one at the time knew how it would work. However, this theory became one of the cornerstones of modern physics. Today we can hardly imagine a world where quantum theory has not been discovered—without its research, the ubiquitous technologies of life, such as semiconductors, simply wouldn’t exist. From this perspective, "useless" is thus relative, as what is “useless” for the present may be of great use in the future.

In these "fun but useless" studies, Chen and his team use the new methods they have developed to do a lot of bizarre things. There are countless scientific teams studying nanometers all over the world, and everyone can make straight nanowires, but Chen has coiled nanowires into circles: "We first cover the surface with a layer of polymer and swell it in an organic solvent. Its state is stable, like a film attached to the nanowire. After adding water, the hydrophobic polymer becomes inert in polar water. When the polymer shrinks into a ball, the nanowires inside are forced to coil into a circle, becoming a nano circle."

As for what the nanosphere can do, the answer will come in the future: "We're focused on method and capacity building."

Strange nanostructures are changed one by one by "magicians". Chen said, "It's like there are 10,000 kinds of tenon-and-mortise structures that can be applied. It doesn't make much sense to do the 10,000th one, but the real fundamentals are the basic processing ability of sawing, planning and chiseling. With these basic tools, any structure can be made. Many people think that nanotechnology has been developed for many years, and it is still far from what they imagined, because they are too concerned about the current application and underestimate the development of methods and capabilities.”

Exploring manufacturing at the nanoscale is a combination of macro and micro worlds. Chen and his team are trying to jump out of the traditional framework and stand at the forefront of basic research into nanosynthesis capabilities



Hongyu Chen: Doing ’Useless' Research Can Push a Field Forward