Researchers unveil molecular strategies that enable materials to move, transform, and self-assemble—bridging chemistry and robotics

In nature, living systems effortlessly sense, move, and adapt to changing environments. Replicating such dynamic behavior in artificial materials has long challenged scientists. A recent study introduces supramolecular robotics—a molecular design strategy that enables soft materials to exhibit autonomous motion, reversible transformations, and tissue-like organization. This innovation marks a key step toward creating programmable, life-like systems that blur the line between chemistry and robotics.

From cells that migrate to tissues that heal, nature abounds with systems capable of sensing and adapting to their surroundings. Replicating this level of adaptability in synthetic systems has remained a grand challenge in chemistry and materials science. Most artificial materials, though inspired by biology, still react to only one stimulus and lack the integrated responsiveness that characterizes living matter.

A new study published online on August 7, 2025, in Volume 6, Issue 9 of the journal Accounts of Materials Research addressed this challenge. The research team from Japan proposed a new framework called supramolecular robotics, which allows soft materials to exhibit motion, transformation, and self-assembly by dynamically modulating molecular interactions. The team was led by Associate Professor Taisuke Banno of the Department of Applied Chemistry of Keio University, in collaboration with Dr. Tomoya Kojima, JSPS Postdoctoral Fellow of Tokyo University of Agriculture and Technology; and Shoi Sasaki, Ph.D. Student of the School of Science for Open and Environmental Systems of Keio University.

“While many bioinspired materials mimic specific biological functions, most respond to only a single stimulus and lack the integrated responsiveness seen in living systems,” explains Dr. Banno. “In nature, organisms achieve complex behaviors such as motility, signaling, and regeneration through coordinated molecular recognition, signal processing, and actuation. Our concept of supramolecular robotics extends molecular robotics by emphasizing the role of noncovalent interactions—like hydrophobic, electrostatic, and hydrogen bonding forces—as the driving elements for adaptive, life-like behavior.”

In this approach, molecules act as adaptive building blocks that can organize, disassemble, and reorganize based on subtle chemical cues. The resulting materials display programmable motion, shape transformation, and cooperative assembly—functions that bridge molecular chemistry and robotic behavior.

The researchers outlined three key principles that underpin supramolecular robotics: motility, phase transition, and prototissue formation.

At the micrometer-scale, motility was achieved using reactive oil droplets in aqueous environments. Here, spontaneously generating convection based on the heterogeneity of interfacial tension at the droplet surface—a phenomenon known as the Marangoni effect—propels droplets autonomously. Depending on the stimulus, the droplets could move directionally or form collective patterns, resembling microbial swarms. Such chemically powered motion systems may serve as the foundation for microscale robots capable of environmental sensing or targeted transport.

The second phenomenon, phase transition, captured how supramolecular assemblies dynamically switch between structural states—such as micelles, vesicles, or gels—in response to stimuli like light or pH. These transformations, either reversible or irreversible, emulate how biological systems adapt to changing surroundings. The ability to couple chemical reactions with structural reorganization could enable self-healing materials and controlled drug-release platforms that function far from equilibrium.

The final stage involved prototissue formation, where multiple protocell-like vesicles assembled into larger, tissue-like structures due to non-covalent intermolecular interactions. These assemblies exhibited reversible collective motion and communication between compartments—behaviors reminiscent of living tissues. By programming such cooperative dynamics, the team demonstrated how soft materials could self-organize and repair themselves without external control.

“In natural environments where chemical conditions are constantly changing, our approach could lead to molecular assemblies that autonomously adapt and perform optimal functions,” says Dr. Banno. “This could pave the way for applications in targeted drug delivery, environmental remediation, and the development of soft robotic systems that move and respond on their own.”

By merging supramolecular chemistry with systems thinking, the team has provided a roadmap for constructing materials that go beyond simple responsiveness. Instead of being passive objects, these materials process information and adapt dynamically—a defining characteristic of intelligence in living systems. Looking ahead, this molecular-level engineering could transform a wide range of fields. In medicine, adaptive soft materials could deliver therapeutics precisely where and when they are needed. In environmental science, responsive microsystems could monitor or neutralize pollutants in real time. And in robotics, molecularly driven motion could lead to truly soft, self-regulating machines.

Overall, this research opens the door to bioinspired materials capable of sensing, moving, and evolving. As the field of supramolecular robotics matures, such systems could one day lead to programmable therapeutic materials, environmental microswimmers, and self-powered robotic devices—signaling a new era where molecules themselves form the basis of intelligent machines.

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Reference
Title of original paper: Toward Supramolecular Robotics: Molecular Strategies for Adaptive Soft Materials
Journal: Accounts of Materials Research
DOI: 10.1021/accountsmr.5c00070

About Keio University Global Research Institute (KGRI), Japan
Keio University Global Research Institute (KGRI), established in 2016, is a multidisciplinary research hub at Keio University in Tokyo, dedicated to addressing global issues through collaborative, interdisciplinary research that spans faculties and graduate schools. With over 40 research centers and projects, KGRI advances both fundamental and applied research, engages in partnerships worldwide, and drives innovation through initiatives like J-PEAKS. As a leader in promoting integrated expertise and open dialogue, KGRI is committed to shaping the future by disseminating research and contributing to societal progress in line with Keio’s vision as a driving force for academic and societal transformation.

Website: https://www.kgri.keio.ac.jp/

About Tomoya Kojima from Tokyo University of Agriculture and Technology, Japan
Dr. Tomoya Kojima received his Ph.D. degree in Engineering from Keio University, Japan, in 2025 under the supervision of Prof. Taisuke Banno. He is now a JSPS Postdoctoral Fellow at Tokyo University of Agriculture and Technology. His research interest is on creation of bioinspired chemical systems using soft materials such as self-propelled droplets, vesicles, and coacervates.

About Taisuke Banno from Keio University, Japan
Taisuke Banno is an Associate Professor at the Department of Applied Chemistry, Keio University. He received his Ph.D. degree in Engineering from Keio University, Japan, in 2011. His scientific interests include organic synthesis, supramolecular systems chemistry, self-assemblies, and nonequilibrium and nonlinear science.

About Shoi Sasaki from Keio University, Japan
Shoi Sasaki received his M.Eng. degree from Keio University, Japan, in 2025 and is currently pursuing his Ph.D. degree in Engineering at the School of Science for Open and Environmental Systems, Keio University, under the supervision of Prof. Taisuke Banno. His research interest is creating molecular self-assemblies that achieve life-like function.

Funding information
The study was supported by JSPS KAKENHI Grants JP20H02712 and JP22KJ2723.