The field of molecular robotics, led by researchers in Japan, is revolutionizing the image of robots. Instead of metal machines, molecular robots are made up of assembled molecules, similar to living organisms. These robots have the potential to be used for medical purposes, such as diagnosing and treating diseases inside the body.
Building a molecular robot is a challenging task, just like creating any living organism. The main obstacle lies in constructing the body of the robot, especially at the microscopic level.
To overcome this challenge, a team at Tohoku University has developed a simple method for building molecular robots using artificial multicellular-like bodies. They achieved this by using molecules that can self-organize into the desired shape.
The team, led by Associate Professor Shin-ichiro Nomura and postdoctoral researcher Richard Archer from the Department of Robotics at the Graduate School of Engineering, published their breakthrough in the American Chemical Society’s journal, Langmuir.
“Our method relies on phospholipids and synthetic surfactants coated onto a hydrophobic silicone sponge,” said Archer.
When the lipid-coated sponge was exposed to water, the hydrophilic and hydrophobic forces caused the lipids and surfactants to assemble themselves, allowing water to soak in. The sponge was then immersed in oil, resulting in the formation of stabilized aqueous droplets. These droplets formed larger planar structures when placed on a water surface, resembling bricks coming together to build a wall.
“Our technique can easily create centimeter-sized structures by assembling micron-sized compartments. It can also be used with different droplet types by using different sponges and water with various solutes. This modular approach opens up countless possibilities,” explains Archer.
The team also discovered a way to give these molecular robot bodies motion control. They introduced magnetic nanoparticles into the hydrophobic walls of the multi-compartment structure. Archer believes that this approach to robot design will lead to flexible modular robots with multiple functionalities, shaping the future of robotics. “Instead of traditional steel and silicon, we envision a new generation of robots assembled by molecules and powered by functional chemicals,” he says.