Scientists at Nanyang Technological University, Singapore (NTU Singapore) have created tiny soft robots that can be directed using magnetic fields to deliver drugs precisely, potentially enhancing future treatments.
The innovative soft robot, developed by experts from NTU’s School of Mechanical and Aerospace Engineering (MAE), was detailed in a recent publication in the journal Advanced Materials.
This study presents the first known instance of miniature robots capable of carrying and releasing up to four different medications in customizable orders and dosages.
In contrast to previous models that could only handle three types of drugs and lacked programmable release, the new miniature robots provide enhanced precision, which could greatly improve treatment effectiveness and reduce side effects, according to the research team.
The NTU group had previously engineered magnetically guided miniature robots that perform complex tasks, such as maneuvering through narrow passages and grasping small items.
Building on their past achievements, lead researcher Assistant Professor Lum Guo Zhan mentioned that the team took inspiration from the 1960s movie ‘Fantastic Voyage,’ where a crew shrinks to the size of a cell to fix a brain injury.
“What used to be purely science fiction is now inching closer to reality with our innovations. Traditional drug delivery methods like pills and injections may soon seem less effective compared to sending these tiny robots to deliver medication exactly where it’s required,” Asst Prof Lum explained.
Highly adaptable and customizable drug-delivery features
The grain-sized robot was crafted using advanced magnetic composite materials (composed of magnetic microparticles and polymers) that are safe for human use.
Unlike existing small robots that lack precise orientation control, the newly developed soft robot shows exceptional dexterity—it can roll and crawl quickly to maneuver around obstacles. This flexibility presents a substantial opportunity for traversing complex, chaotic environments inside the human body.
In laboratory trials, the robot successfully executed tasks in water replicating human body conditions.
Initially, the robot was placed on a platform divided into four areas and was capable of moving to each section at speeds ranging from 0.30 mm to 16.5 mm per second, dispensing different drugs in each area, demonstrating its capability to manage multiple medications and control their release.
In another test, the researchers assessed the robot’s drug delivery effectiveness in more challenging conditions by using a thicker fluid. The results revealed that the robot successfully navigated the environment and dispensed sufficient quantities of medication over an eight-hour period.
Moreover, after eight hours of continuous operation, the robot displayed minimal drug leakage. Its ability to manage drug delivery effectively without excessive wastage positions the soft robot as an excellent tool for treatments requiring precise medication administration at varied times and locations.
The study included contributions from Research Fellow Yang Zilin and PhD graduate Xu Changyu from the MAE School.
“Our findings indicate that this soft robot could significantly contribute to the future of targeted drug delivery, particularly for therapies like cancer treatment that necessitate meticulous management of multiple medications,” Yang noted.
Offering an expert perspective, Dr. Yeo Leong Litt Leonard, a Senior Consultant and surgeon from the Division of Neurology at the National University Hospital and Ng Teng Fong General Hospital, remarked, “As a physician conducting minimally invasive procedures, I currently utilize catheters and wires to navigate through blood vessels for treatment. However, I anticipate it won’t be long before tiny robots capable of independently moving through the body replace these tools, reaching areas that are otherwise inaccessible. These robots could remain in place to release medication gradually, which would be a much safer alternative to leaving a catheter or stent inside the body for extended periods. This marks a significant medical advancement on the horizon.”
The NTU research group is exploring ways to shrink their robots further, aiming to apply them in innovative treatments for conditions like brain tumors, bladder cancer, and colorectal cancer. Before utilizing these tiny robots in medical applications, the NTU researchers plan to conduct further performance evaluations with organ-on-chip models and in animal studies.
