In the realm of robotics, shape-shifting machines are the latest innovation that is set to revolutionize various industries, including healthcare and construction. These robots, which can alter their physical form in response to external stimuli, are composed of phase-changing materials such as magnetic metallic alloys. This allows them to morph from solid to liquid states and vice versa, depending on the conditions they encounter.
The development of shape-shifting robots is still in its infancy. However, a pioneering study has revealed that researchers from Sun Yat-sen University and Carnegie Mellon University have developed small robots inspired by sea cucumbers. These robots, constructed from a new material known as magnetoactive phase transitional matter (MPTM), are composed of magnetic particles embedded in liquid metal. This unique composition allows the robots to liquefy and coalesce back together, similar to the infamous villain in Terminator 2.
These miniature machines possess impressive capabilities. They can move swiftly, jump, climb walls, and split into smaller units that work collectively to move objects before merging back together. Additionally, they can bear payloads exceeding 30 kilograms and form structural or electrical connections, making them akin to a conductive adhesive. Their unique properties make them ideal for applications where compactness is crucial.
Carmel Majidi, a professor of mechanical engineering at Carnegie Mellon University and a senior author of the study, believes this technology introduces new possibilities for achieving robotic functions at a small scale in hard-to-reach places. Given their shape-shifting properties and response to external stimuli, they can be remotely operated and controlled to move within otherwise hard-to-reach parts such as those within the body.
The potential applications of these robots are wide-ranging. In healthcare technologies, they could be instrumental in removing foreign bodies or delivering targeted drug therapies. They could also be useful in the creation of flexible electronic circuits and small-scale robotic systems.
Shape-shifting robots are constructed from phase-changing materials that absorb latent heat, allowing them to transform their states. This transformation is triggered by an external source, such as changes in a surrounding magnetic field, an electrical field or temperature, and is remotely controlled. This ability to transform from one state to another sets them apart from other robotic models that may simply self-assemble or re-orient into a new design.
In their study, Majidi and his team used low-melting-point metals, primarily gallium, mixed with particles that can generate their own magnetic fields. By applying an electromagnetic field and rapidly alternating it, they were able to trigger the magnetic particles to generate an electric current, causing the metal to melt. During this phase change, the metallic body becomes pliable as its material’s stiffness and deformability changes.
The ability of these robots to transition physically from solid to liquid and back again not only transforms their shape but also their function. As Lining Yao, director of Carnegie Mellon University’s Morphing Matter Lab, puts it, “Form is function.” By dynamically controlling the shapes of these robots, it is possible to create multi-functional, adaptive and responsive systems that have broad applicability in different fields.
In healthcare, for instance, the high maneuverability and remote control capabilities of these robots make them ideal for directed drug delivery. This method aims to deliver a high concentration of a drug to a targeted site within a patient while minimizing side effects and controlling overall toxicity.
In construction, shape-shifting robots can function as “smart soldering machines,” reaching hard-to-reach circuits and acting as both solder and conductor in wireless circuit assembly and repair. They can also melt into threaded sockets and solidify, effectively morphing into a universal screw.
Shape-shifting robots could also play a crucial role in biomedicine by removing foreign objects from the body. During this minimally invasive process, a patient ingests one of these miniature magnetic machines like a pill. It then locates the foreign object, molds around it, and exits the body naturally as a waste product.
These robots can also be made from organic materials, such as a bio-inspired seed carrier that buries itself into the soil when cued by rain. This could potentially automate reforestation, further showcasing the versatility and potential of shape-shifting robots in various fields.