Ceramic Bearings for Medical Robots

Chris Johnson, Managing Director of specialist ceramic bearings supplier SMB Bearings, explains why ceramics are the answer to high-precision bearings.

Robots are on the rise in medical environments, and are increasingly being trusted to carry out more complex procedures. Although martensitic stainless steels have been favored for bearings in robotic applications, their performance is falling short against increasing standards for preventing contamination in medical environments.

Analyst GlobalData predicts that the medical robotics market will grow from $4.7 billion in 2020 to $14.5 billion in 2030, and casts those robots as “viewed more as companions providing emotional support rather than as tools”. Will go.” The quote refers to artificial intelligence (AI) becoming more advanced, allowing robots to provide medical assistance to patients faster than we can imagine today, and combating staff shortages.

From surgical assistance robots that help perform minimally invasive surgery to AI-powered therapeutic robots used in rehabilitation for injuries and paralysis, medical robots have evolved since simple robotic arm techniques were first introduced in the 1980s has come a long way. Although surgical robots are becoming cheaper, modern medical applications are also demanding higher precision and speed capabilities from these robots.

Traditionally, in medical equipment, bearings – which optimize the rotation of axes such as robotic arms by limiting or avoiding friction and shock – have been made from high-purity metals such as martensitic stainless steel. Examples include medical robots that help perform keyhole surgeries where extreme precision is required. Surgical robot bearings must provide the highest possible rotational accuracy while also being small enough to fit into these often compact and portable hospital equipment.

However, steel bearings have limitations including contamination. While steel bearings are tough and capable of withstanding highly corrosive environments, they are susceptible to particle contamination due to very high contact pressures against the steel within the bearing during operation. If left unchecked, this contamination can cause denting and wear.

Of course, contamination in general is unacceptable in a health and safety environment. As robots become more prevalent in medical applications, regulations are becoming stricter to prevent contamination.

instead of steel

The need to avoid contamination is accompanied by other design requirements such as high speed, low noise and non-magnetic properties. For example, because magnetic resonance imaging (MRI) scanners use a strong magnetic field to generate two- or three-dimensional images of a living subject, steel bearings cannot be used because of their magnetic properties. .

All of these factors influence the choice of material for bearings in the medical environment – ​​but which material can replace steel? The medical device sector is increasingly opting for bearings made exclusively from zirconia (ZrO2), or other exotic ceramic compounds. According to the Institute of Materials, Minerals and Mining, “Ceramic bearings made from ZrO₂ are tough with expansion properties similar to chrome steel and 440 stainless steel, although they are 30% lighter.”

Indeed, full ceramic precision bearings are harder than steel, with better corrosion and heat resistance, higher dimensional stability, and lower density. However, ceramic bearings are expensive. This is a big issue for healthcare institutions operating within tight budgets, so the decision to invest in them should be well considered. Fortunately, ceramic bearings have many advantages for the medical environment.

One is that bearings do not react to chemicals. This means they do not corrode or weaken when exposed to the harsh chemicals used for sterilization in hospitals. Ceramics does not require lubrication which would otherwise attract contaminants such as dust, water or moisture and it also eliminates the need for maintenance procedures such as lubrication. They are also water resistant, so they can be washed regularly.

high value applications

So, Is It Worth It To Invest In Ceramic Bearings For The Medical Environment? There are still some applications where the speed and accuracy of steel are important, for example in surgical robots. However, there are other instances where the use of incorrect components in such medical or laboratory equipment may contaminate the study condition or cause the study to be discontinued altogether.

Instead, additional investment in ceramic bearings could help ensure that medical robots run with effectiveness and longevity – especially when they’re viewed as tools rather than as companions providing emotional support. More are poured.”