Scientists at the RIKEN Center for Emergent Matter Science have discovered a composite material that is capable of directing mechanical energy along a specific path. This hydrogel embedded with nanofillers may be the key to transforming the way we harness wasted vibrational energy.
A team of researchers, guided by experts from the RIKEN Center for Emergent Matter Science, has created an innovative material that incorporates nanofillers within a hydrogel. This material is uniquely designed to channel mechanical energy unidirectionally, showcasing a “nonreciprocal” behavior. This composite material, which can be produced at various scales, enables liquid droplets to ascend through the material, driven by vibrational, up-and-down motions. The potential for this material lies in its ability to harness random vibrations to move matter in a desired direction.
Directing energy along a preferred pathway is crucial for life as we know it. Fundamental biological processes such as photosynthesis and cellular respiration hinge on this principle, channeling random natural fluctuations nonreciprocally to steer a system away from entropy, much like Maxwell’s famous demon. This preferential energy movement is widely utilized in numerous fields, including electricity (transforming AC current into DC), photonics, magnetism, and sound. However, developing devices that can direct mechanical energy has posed a significant challenge, despite their potentially numerous applications.
Now, the RIKEN-led team has successfully produced a unique, easily reproducible material that can perform this task. The team employed a hydrogel – a water-based soft material – constructed from a polyacrylamide network and inserted graphene oxide nanofillers at an angle. The hydrogel is anchored to the floor, with the top section able to move under shear force, while the bottom remains fixed. The fillers are positioned at an angle, angled clockwise from top to bottom.
When shear force is applied from the left, aligning with the direction of the nanofillers’ inclination, they tend to buckle, thereby losing resistance. In the opposite direction, the force stretches the nanofillers further, preserving their strength. This mechanism allows the material to deform in one direction but not the other. The team recorded this differential, finding the material to be about 60 times more resistant in one direction than the other.
In a practical test, they fashioned a block of this material and placed it on a vibrating platform. Depending on its design and orientation, the material could direct droplets to move right or left, or even upward through the network but not downward. The vibrational movement could also induce controllable circular motion, either clockwise or anticlockwise. When droplets of colored liquid were introduced into the vertically oriented hydrogel, they ascended as if by magic, with the usually useless alternating vibrations directed to create a net upward motion.
In a further experiment, the team, in partnership with researchers from the RIKEN Hakubi Fellows program, placed C. elegans worms on the material. Despite their normally random movement, the worms were all directed to one side of the hydrogel based on its orientation.
Yasuhiro Ishida of the RIKEN Center for Emergent Matter Science, who led the research, found the results astonishing and promising. He expressed his excitement at seeing how mechanical energy could be effectively channeled in one direction using a material that is not only easy to manufacture but also scalable. Looking ahead, Ishida’s team plans to discover applications for this material, in hopes of harnessing vibrational energy that has thus far been considered waste.
Reference: “Mechanical nonreciprocity in a uniform composite material” by Xiang Wang, Zhihao Li, Shuxu Wang, Koki Sano, Zhifang Sun, Zhenhua Shao, Asuka Takeishi, Seishiro Matsubara, Dai Okumura, Nobuyuki Sakai, Takayoshi Sasaki, Takuzo Aida and Yasuhiro Ishida, 13 April 2023, Science.
DOI: 10.1126/science.adf1206
Table of Contents
Frequently Asked Questions (FAQs) about Mechanical Energy Channeling
What is the new material developed by scientists at the RIKEN Center for Emergent Matter Science?
The scientists have developed a composite material that is a hydrogel embedded with nanofillers. This unique material can direct mechanical energy along a specific path, thus potentially transforming the way we utilize wasted vibrational energy.
How does the new material channel mechanical energy?
The new material is capable of directing mechanical energy unidirectionally, showcasing a “nonreciprocal” behavior. This is achieved by embedding nanofillers in a hydrogel at a specific angle. When a shear force is applied, the nanofillers either buckle, losing resistance, or stretch further, preserving their strength. This allows the material to deform in one direction but not the other.
What practical applications were demonstrated using this new material?
In their experiments, the researchers used a block of this material placed on a vibrating platform. Depending on its design and orientation, they managed to direct droplets to move right or left, or even upward but not downward, through the network. Additionally, when they introduced droplets of colored liquid into the vertically oriented hydrogel, they ascended, channeling usually useless alternating vibrations to create a net upward motion. They also observed directed movement in C. elegans worms placed on the material.
What are the future plans for this material according to Yasuhiro Ishida, the leader of the research?
Yasuhiro Ishida and his team are planning to discover applications for this material, with the hope of harnessing vibrational energy that has thus far been considered waste. The material is relatively easy to manufacture and scalable, which makes it promising for a wide range of applications.
More about Mechanical Energy Channeling
- RIKEN Center for Emergent Matter Science
- Mechanical nonreciprocity in a uniform composite material – Science
- Understanding Hydrogels
- Introduction to Nanofillers
- Maxwell’s Demon and the nature of information
5 comments
Whoah! This is mind-blowing. If they can really harness ‘wasted’ energy like this… Huge game changer, y’know?
still scratching my head on this one…not quite sure i get it, but sounds cool i guess?? i’ll have to read up some more.
Amazing! So they’re moving stuff against gravity with vibrations? That’s just awesome!
If we could recapture and use all that wasted energy, think about how much cleaner our power generation could be. just saying!
This makes me think of some sci-fi stuff! it’s like somthing out of star trek or somthing.