Healthcare (Commonwealth Union) – A research team at Nanyang Technological University in Singapore (NTU Singapore) has created soft, grain-sized robots that can be guided by magnetic fields to deliver drugs precisely, offering the potential for enhanced treatments in the future.
The innovative robots, that were produced by engineers at the NTU School of Mechanical and Aerospace Engineering (MAE), were detailed in a study published in Advanced Materials. This research marks the first known instance of miniature robots capable of carrying and releasing up to four different drugs in customizable sequences and doses.
Unlike previous small-scale robots, which could only handle up to three drugs without customizable release options, these new miniature robots provide advanced, precise functionality. According to the research team, this precision has the potential to improve therapeutic outcomes and reduce side effects.
The NTU scientists had earlier created magnetically controlled robots able to perform complex actions, like navigating narrow spaces and handling tiny objects. Building on this work, Assistant Professor Lum Guo Zhan, the study’s lead researcher, shared that the team drew inspiration from the 1960s sci-fi movie Fantastic Voyage, in which a crew is shrunk to cellular size to perform brain surgery.
Assistant Professor Lum indicated that what once seemed like science fiction is now edging closer to reality with the lab breakthrough they made. He further pointed out that traditional drug delivery methods, such as pills or injections, may seem outdated compared to a small robot navigating the body to deliver drugs exactly where they are required.
The tiny, grain-sized robot was engineered with smart magnetic composite materials—consisting of magnetic microparticles and a polymer—that are safe for human use. Unlike many current miniature robots, which struggle to control their movements precisely, this new soft robot is highly agile, able to roll and crawl effectively to navigate around obstacles. Its flexibility holds great promise for maneuvering through the complex, irregular environments within the human body.
In laboratory tests, the robot successfully performed tasks in water, simulating conditions similar to those inside the body. One test involved placing the robot on a surface divided into four sections, where it moved across each section at speeds ranging from 0.30 mm to 16.5 mm per second, releasing a different drug at each location. This demonstrated its capability to carry multiple drugs and release them in a programmable, controlled sequence.
In a further test, researchers evaluated the robot’s ability to deliver drugs in more demanding conditions by placing it in a denser liquid. Results showed that the robot could navigate and administer the necessary drug doses over an extended period of eight hours. Notably, after this continuous operation, the robot showed minimal drug leakage, highlighting its suitability for treatments requiring precise, timed release of multiple medications in various locations.
Research Fellow Yang Zilin and PhD graduate Xu Changyu from the School of MAE co-authored the study.
“These findings show that our soft robot could potentially play a key role in the future of targeted drug delivery, especially in those treatments such as cancer therapies that need precise control over multiple drugs,” explained Yang.
Dr Yeo Leong Litt Leonard, Senior Consultant and surgeon at the Division of Neurology, Department of Medicine, National University Hospital and Ng Teng Fong General Hospital, gave an independent view saying, “As a doctor who performs minimally invasive procedures, we currently use a catheter and a wire to move through blood vessels to treat problems. But I can foresee it will not be long before this is superseded by tiny robots that can autonomously swim through the body to reach places we can’t get to with our tools. These robots could stay in place and release medication over time, which would be much safer than leaving a catheter or stent inside the body for a long time. This is a medical breakthrough on the verge of happening.”
