Revolutionary Small Magnet Matches Strength of Large Magnets for the First Time

In a groundbreaking development, researchers have designed a magnet small enough to fit in your palm that rivals the strength of the world’s most powerful magnets.

High-performance magnets are crucial in various scientific fields, being utilized in applications ranging from MRI machines and particle accelerators to advanced nuclear fusion research. The strongest magnets available typically use superconductors, which are materials that conduct electricity nearly without loss.

However, most superconducting magnets are sizable. Often, their smaller counterparts share similar dimensions with traditional superconductors. Take for instance Star Wars‘ R2D2; at its largest, it resembles a two-story structure. According to Dr. Alexander Burns from ETH Zurich, Switzerland, his team has engineered a superconducting magnet capable of matching the strength of larger counterparts, yet it’s only 3.1 millimeters in diameter. They achieved this by coiling a thin tape made of a ceramic known as REBCO, which becomes superconducting at cryogenic temperatures, generating a magnetic field when current flows through the coils.

Dr. Burns stated that the team procured REBCO tape from a commercial source, embarking on a rigorous exploration to determine the optimal magnet design, which involved creating and testing over 150 prototypes. “We adopted a ‘fail fast, fail often’ approach in our strategy,” he noted.

Eventually, they refined a design using two or four pancake-shaped coils, achieving magnetic field strengths of 38 Tesla and 42 Tesla, respectively. To provide context, conventional refrigerator magnets typically generate fields less than 0.01 Tesla. The most powerful magnets currently in existence generate field strengths of around 45 Tesla, each weighing several tons and consuming up to 30 megawatts of power. In contrast, Burns and his team’s magnet is hand-sized and operates on less than 1 watt.

The ultimate goal for this groundbreaking technology is to enhance nuclear magnetic resonance (NMR), a technique that utilizes magnetic fields to unveil molecular structures, including those of drugs and industrial catalysts. This technology has long been hindered by the large size and cost of traditional magnets, but the research team intends to democratize access to such advanced tools for chemists. Ongoing tests are being conducted to integrate the magnet into NMR setups.

“Historically, achieving magnetic fields exceeding 40 Tesla necessitated massive and costly facilities, making it crucial to utilize superconducting tape to attain similar strengths in a compact device,” stated Dr. Mark Ainslie from King’s College London. “This innovation indicates that ultra-high-field magnets may soon be accessible to a broader range of laboratories.”

Despite these advancements, several challenges remain before widespread adoption. Questions concerning how to maintain uniform magnetic fields and manage the electromagnetic behavior of the coils must be addressed.