Flexible robotics tchnology is getting a boost from innovative materials that push the boundaries of engineering.
Scientists and engineers are making exciting developments, including materials designed by algorithms and others that reshape when exposed to light. How do these materials work, and what can they do?
Computational design and AI design have exploded in popularity over the past few years as the technology has become more capable and accessible. These tools are being used to develop materials that make robots more flexible using principles from biology.
For example, a 2022 research project between the University of Illinois and the Technical University of Denmark used algorithm-based design to develop unique frog-like structures out of AI-generated elastomers.
An elastomer is a type of polymer specifically designed to be flexible and malleable. Elastomers can bounce back to their original shape when distorted, greatly improving a robot’s durability. These materials have long been a staple of soft robotics. Common examples of elastomers include neoprene, isoprene and even Teflon, although there are countless possible polymer combinations.
The project at the University of Illinois approached elastomers in a new way. Researchers used algorithm-based design to pinpoint the ideal polymer combination based on the structure’s needs. They took things a step further by generating the geometric design of the piece itself, which ended up looking and functioning similarly to a frog’s legs.
The main benefit of algorithm-based design is logic-based creativity. The algorithm identifies ideal designs based on numbers, allowing it to present possible solutions that a human might not have thought of. This method could identify top candidates for elastomers, polymers and polymer blends to improve a robot’s flexibility based on its unique functional needs.
There is huge potential for flexible electronics today. Researchers are developing flexible PCBs for everything from electronic clothes to medical devices. This technology is a great fit for flexible robotics. There are plenty of elastomers and flexible structural parts for robots today, but a rigid circuit board limits their capabilities. Malleable PCBs allow all the materials in the robot to be pliable, down to the electronics level.
Flexible PCBs, also known as flex circuits, can be bent, stretched and shaped easily. These boards can make robots more customisable and portable by allowing circuits to adhere to any flexible material a developer might want, such as flex glass, foil or paper. Structural and functional designs can also be more flexible since the robot can include PCBs that bend and reshape. This expands its capabilities, allowing it to take on forms that wouldn’t be possible with conventional building materials.
Flexible circuits could be particularly useful for aquatic robots. Traditional mechanical approaches used for land-based machines often don’t translate well to underwater models. Efficient biomimetic designs prove an innovative solution by borrowing ideas from real sea creatures.
Biomimetic designs rely on materials that can move the way flexible tissue and muscle do. Flex circuits could allow a robot to have a fully nonrigid structure, perfect for a machine inspired by creatures like jellyfish, squid or fish.
Adaptability is one of the most common challenges that robotics engineers face. A certain material might be perfect for one environment or circumstance but poorly suited for another. How can robots be designed to adapt to their environment on their own? Smart materials might be the answer.
Smart composite materials are unique material blends that can autonomously change their properties based on physical stimuli. A 2022 research project successfully developed one such smart material that can alter its flexibility when exposed to light. It takes on a crystalline structure when exposed to a blue LED light, becoming rigid like conventional hard plastic. The portion that is not exposed to light remains flexible.
Smart materials that are responsive to physical stimuli like this could be used for many flexible robotics applications. For example, a farming robot used to pick fruit could have a soft gripper activated by flashing lights on pieces of smart plastic. This could be a big step forward in gripper technology because smart materials free the gripper from needing hydraulics. They also simplify the robot’s design minimising the mechanical components required.
Smart materials could even be used to streamline waterproof robot designs. Electronics typically don’t do well in underwater environments. This is partly because conventional electronic components fail when exposed to water, but robots can also be crushed by high atmospheric pressure at extreme depths.
Smart materials could reduce the amount of mechanical and electronic components an underwater robot would need, simplifying waterproofing and pressure shielding. Light-activated smart material could be particularly effective in extreme depths where there is virtually no natural light.
Modular robotics can make robots more flexible by allowing them to rapidly alter their structure as needed. These robots can even be self-replicating and self-scaling, like the modular robotics system researchers at MIT developed in 2022.
The ability to rearrange parts as needed greatly improves a robot’s versatility and the range of tasks it can handle. However, it is worth noting that effective modular robotics often relies on a robust AI algorithm to unlock its full potential. For example, the AI in the system developed at MIT can tell when the structure it’s assembling gets too big for it to complete efficiently. When this occurs, the robot can use its modular building materials to make copies of itself to finish large projects faster.
Modular robots can even work on a microscopic level. One 2019 research project combined smart materials with modular robotics to create flexible millimetre-scale machines. UV light is used to tell the robot what shape to take on, and the robot’s magnetic particles shift to assume the correct geometry.
Technology like this could be instrumental in biotechnology, where it could be applied to nanobots. Building robots on a microscopic scale using conventional methods is extremely difficult. Smart modular materials make constructing nanobots easier and improve their flexibility since they can be reshaped for any task a situation might call for.
Innovations are crucial to advancing the field of flexible robotics. Materials must evolve and become more versatile as the need for robots continues to expand. Smart, flexible and AI-generated materials show where the future of the industry is going. These developments will help next-gen machinery take on new challenges.