Shielding the Future: Innovations in Radiation Protection Materials

In our increasingly technological world, the need for effective radiation shielding has never been more critical. From medical facilities to nuclear power plants, and from space exploration to everyday electronics, the quest for superior radiation protection materials continues to drive innovation in materials science and engineering.

Radiation shielding is the practice of reducing the effects of ionising radiation on people and equipment through the use of specialised materials. These materials attenuate or block various types of radiation, including alpha and beta particles, gamma rays, X-rays, and neutrons. As our understanding of radiation's effects on human health and electronic systems has grown, so too has the sophistication of the materials we use to shield against it.

The history of radiation shielding materials is closely intertwined with the discovery and utilisation of radioactivity itself. In the early 20th century, as scientists began to unravel the mysteries of radioactivity, the need for protection became apparent. Marie Curie, the pioneering physicist and chemist who conducted groundbreaking research on radioactivity, tragically died from aplastic anaemia, likely caused by her prolonged exposure to radiation.

The first significant breakthrough in radiation shielding came with the recognition of lead's effectiveness. Lead's high atomic number and density made it an excellent absorber of gamma radiation and X-rays. During the Manhattan Project in the 1940s, lead became the go-to material for shielding in nuclear research and development. However, lead's toxicity and weight have long been concerns, spurring research into alternative materials. In the 1950s and 1960s, concrete became widely used for shielding in nuclear power plants due to its effectiveness against neutron radiation and its relatively low cost.

The space race of the 1960s brought new challenges and innovations in radiation shielding. NASA developed lightweight polymer composites to protect astronauts from cosmic radiation whilst minimising the payload weight of spacecraft.

In recent decades, the focus has shifted towards developing more efficient, lightweight, and environmentally friendly shielding materials. Researchers have explored various composites, nanomaterials, and novel alloys to achieve superior radiation protection with reduced weight and toxicity.

Shielding Materials Research in Australia

Australia has established itself as a significant contributor to the global research landscape in shielding materials. With world-class universities and research organisations, the country is at the forefront of developing innovative technologies. This section highlights some of the key institutions and projects driving shielding materials research in Australia.

Australian Nuclear Science and Technology Organisation (ANSTO)

The Australian Nuclear Science and Technology Organisation (ANSTO) has been a key player in radiation shielding research. Their work on advanced concrete formulations has led to the development of highdensity concrete that offers improved gamma and neutron shielding properties. In 2018, ANSTO researchers published findings on a new concrete mix incorporating recycled heavy metal oxide glasses, which not only enhanced shielding properties but also addressed waste management issues.

The University of Wollongong

At the University of Wollongong, the Institute for Superconducting and Electronic Materials (ISEM) has been pioneering the use of graphene in radiation shielding. Professor Xiaolin Wang and his team have demonstrated that graphene oxide can effectively shield against gamma radiation whilst being significantly lighter than traditional lead shields. Their 2019 study showed that a graphene oxide composite could achieve the same level of protection as lead with just one-third of the weight.

RMIT University

RMIT University has been exploring the potential of metal-organic frameworks (MOFs) for radiation shielding. Dr Ravichandar Babarao's team has developed MOFs that can selectively capture radioactive ions from water, with potential applications in nuclear waste management and environmental remediation. Their work, published in 2020, demonstrated a novel MOF that could remove over 99% of uranium from contaminated water.

University of Sydney

The University of Sydney's School of Physics has been investigating the use of boron nitride nanotubes (BNNTs) for space radiation shielding. Professor Marcela Bilek's research group has shown that BNNTs can effectively shield against both electromagnetic and particle radiation, making them promising candidates for protecting spacecraft and astronauts on longduration missions. Their 2021 study demonstrated that BNNT-reinforced polymer composites could reduce radiation exposure by up to 45% compared to conventional materials.

Monash University

At Monash University, the Department of Materials Science and Engineering has been working on advanced ceramic composites for nuclear applications. Professor Joanne Etheridge and her team have developed novel silicon carbide composites that offer excellent radiation resistance and thermal properties. Their research, published in 2022, showed that these composites could maintain their structural integrity under extreme radiation conditions, making them suitable for next-generation nuclear reactors.

The CSIRO

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has also made significant contributions to the field. Their Materials Science and Engineering division has been developing smart nanomaterials that can adapt to different types of radiation. In 2023, CSIRO researchers unveiled a new class of responsive polymers that can change their structure to optimise shielding against varying radiation types and intensities.

Innovations and Breakthroughs

Looking to the future, the field of radiation shielding materials is poised for further innovation and breakthroughs. Several trends are likely to shape the development of next-generation shielding materials:

Multifunctional materials:

Researchers are increasingly focusing on materials that can provide radiation shielding whilst offering additional benefits such as structural support, thermal management, or even energy harvesting capabilities.

Bio-inspired materials: Taking cues from nature, scientists are exploring biological systems that have evolved radiation resistance, such as certain bacteria and fungi, to develop new shielding strategies.

Artificial intelligence and machine learning: These technologies are being employed to accelerate the discovery and optimisation of new shielding materials, allowing researchers to explore vast material combinations and predict their properties.

Additive manufacturing: 3D printing technologies are enabling the creation of complex, customised shielding structures that can be tailored to specific applications and geometries.

Sustainable materials: With growing environmental concerns, there is a push towards developing shielding materials from renewable resources or recycled materials, reducing the reliance on mined elements.

Nanoscale engineering: Advances in nanotechnology are allowing for precise control over material properties at the atomic level, potentially leading to ultra-efficient shielding materials.

As we continue to push the boundaries of technology and explore new frontiers, from deep space missions to advanced medical treatments, the demand for innovative radiation shielding materials will only grow. Australian research institutions, with their world-class facilities and expertise, are well-positioned to lead the way in developing the next generation of radiation protection solutions.

The future of radiation shielding materials is not just about blocking harmful radiation; it's about doing so in ways that are smarter, lighter, more sustainable, and more adaptable to our evolving needs. As we face the challenges of the 21st century and beyond, these innovations will play a crucial role in safeguarding human health, enabling technological progress, and expanding our horizons in science and exploration.

Researchers Identify Effective Materials For Protecting Astronauts From Harmful Cosmic Radiation On Mars

Researchers have identified specific materials, including certain plastics, rubber, and synthetic fibres, as well as Martian soil (regolith), which would effectively protect astronauts by blocking harmful space radiation on Mars.

These findings could inform the design of protective habitats and spacesuits, making long-duration Mars missions more feasible. Because Mars lacks Earth's thick atmosphere and magnetic field, astronauts exploring the planet would be exposed to dangerous levels of radiation.

Dimitra Atri, Investigator, Centre for Astrophysics and Space Science and Group Leader of the Mars Research Group at NYU Abu Dhabi's Centre for

Astrophysics and Space Science, and lead author Dionysios Gakis from the University of Patras in Greece, report these new findings in ‘Modeling the effectiveness of radiation shielding materials for astronaut protection on Mars’, appearing in the journal The European Physical Journal Plus.

Using computer modelling to simulate the radiation conditions on Mars, the researchers tested various standard and novel materials to see which best shielded cosmic radiation and determined that compound materials like certain plastics, rubber, and synthetic fibres would all perform well. Martian soil (regolith) was also somewhat effective and could be used as an extra layer of protection.

In addition, they demonstrated that the most widely used aluminium could also be helpful when combined with other low atomic number materials. The study also used real Mars data from NASA's Curiosity rover to confirm these findings.

"This breakthrough enhances astronaut safety and makes longterm Mars missions a more realistic possibility," said Atri. "It supports the future of human space exploration and potential establishment of human bases on Mars, including the UAE's Mars 2117 project and its goal of establishing a city on Mars by the year 2117."

"Several materials were specifically tested in a simulated Martian environment, making our results directly applicable to future missions and optimising the combination of advanced materials with the natural resources available on Mars," Gakis added.

Visualization of the rays’ trajectories originating from a pencil beam with a small beam angle. Image Credit: The European Physical Journal Plus (2024).