A Cut Above:
Aluminium in Medical Devices
As the COVID-19 crisis continues to affect daily life around the world, aluminium is helping to protect first responders and save lives. From ventilator parts to the flexible nose strip in N95 masks, aluminium is an integral element in medical devices being used to fight the pandemic.
Strong, lightweight, corrosion-resistant, and malleable, aluminium was a major material in a variety of medical instruments long before the pandemic arrived. This highly adaptable metal continues to inspire designers and manufacturers who are creating solutions to our healthcare needs, for both today and tomorrow.
Firmly implanted in hospitals and doctor’s offices
Aluminium is critical to a wide range of medical equipment today, from diagnostic to surgical devices. The material’s malleability makes it ideal for tubing in stethoscopes and extruded aluminium is a favorite for the handles or grips of surgical instruments. Many dental tools also contain aluminium components.
Aluminium sheets and plates commonly make their way into general hospital furniture and equipment, including IV poles, surgical carrying cases, bedpans, trays, gurneys, and rolling carts. The aluminium foil in pharmaceutical blister packs provides a robust barrier, protecting drugs from heat, moisture, and bacteria.
The metal also appears in sophisticated medical gear, from imaging equipment to heart monitors. Constellium produces aluminium sheets and plates for ventilators, which have been particularly indispensable during the coronavirus pandemic. And N95 masks use aluminium strips for the wire that ensures they fit snugly over the nose.
Aluminium is also well adapted to complex equipment such as the Swiss Dolorclast® Master, a machine housed in extruded aluminium and used by physical therapists to treat musculoskeletal pathologies with shockwaves to alleviate pain. The Dolorclast is made by the medical company Electro Medical Systems (EMS), whose Sustaining Engineering Group leader, Yves-Marie Le Cour Grandmaison, explains, “Aluminium provides a wide range of esthetic finishes and is not susceptible to interference from electromagnetic energy in the vicinity.”
Dissecting aluminium’s advantages
Aluminium offers the medical industry the same advantages it brings to other industries: it is extremely lightweight, with an excellent strength-to-weight ratio. Equipment made from aluminium can be thin, light, and flexible—and at the same time extremely strong and durable.
Manufacturers appreciate the short lead times and low manufacturing costs that aluminium affords. Its geometric possibilities are endless, offering great formability, machinability and design flexibility.
But aluminium also has some lesser-known advantages when it comes to the medical field. Tools made from aluminium have excellent thermal conductivity, so they dry quickly, stemming the spread of bacteria from wet surfaces. And aluminium is highly corrosion resistant, even when nicked or scratched. This is key in the medical industry, where equipment frequently comes into contact with body fluids, disinfectants, and all sorts of harsh liquids.
A study out of Bangalore, India, has taken the hygienic properties of aluminium even further, imitating the properties of insect wings to reduce in-hospital infections. Noting that the rough surfaces of dragonfly and cicada wings keep bacteria at bay, a research team from the Indian Institute of Science made tiny chemical etchings in sheets of aluminium, by placing them into a sodium or potassium hydroxide solution. The results1 were impressive: the etched aluminium surfaces killed or repelled 82% of e. coli, 25% of K. pneumoniae, 86% of P. aeruginosa, and showed significant reduction in S. aureus cells (responsible for staph infection). The surface etchings appear to work by rupturing bacterial cell membranes and disrupting bacteria’s ability to adhere.
A healthy prognosis for the future
With all of these advantages, aluminium has inspired designers to come up with brilliant responses to various other needs in the healthcare and medical industries.
In 2006, Christine Dodson and Sascha Mayer, working together at a graphic design firm in Vermont, started developing a clean, private place for women to breastfeed or pump when out and about. After years of prototyping, they launched the “Mamava” privacy pod for nursing mothers. The original Mamava is an enclosed unit, 2.4 square meters in size, equipped with a fold-down table, bench seating, and electrical outlets. Made of aluminium, it is lightweight, mobile, and durable, and can be customized with artwork, logos, or advertisements. The inventors have installed the Mamava in airports, malls, convention centers, military bases, offices, and museums.
In a totally different register, several years ago an American company called Combat Medical came up with the CRoC® Combat Ready Clamp. It is an atypical tourniquet, a lightweight, durable, collapsible, slip-proof aluminium clamp that suppresses uncontrolled bleeding in seven junctions of the body (such as the groin) where standard tourniquets cannot be used. The company notes that hemorrhaging is the leading cause of preventable deaths in combat.
And recently, in response to the COVID-19 pandemic, the Taiwanese company Miniwiz, a specialist in upcycling, worked with various partners to create a prototype for a MAC (Modular Adaptable Convertible) Ward. This eco-friendly kit for a temporary hospital ward is made from interlocking recycled aluminium panels. When put together, they create negative-pressure environments that contain viral particles and keep them from spreading. The inner walls are sound absorption panels, built from recycled aluminium cans and polyethylene terephthalate (PET) bottles, covered with an anti-bacterial coating and with an ultraviolet self-cleaning system. The kit is lightweight enough to be shipped long distances and assembled within 24 hours, inside existing buildings or next to hospitals.
In a global healthcare crisis, speed, flexibility and the dependability of tried and true materials like aluminium can be life-saving.