Meet the mechanical engineer: Caroline Wither, up close and personal with ostrich bones

October 15, 2018

Caroline Wither

What’s your current role?

I design and develop new surgical instruments for orthopaedic surgeons – surgeons who carry out joint replacements and repair fractured or broken bones. If they have a new or particularly difficult procedure to perform, they will need specially designed instruments. Or sometimes they want tools that are tailored to their individual needs – they’re performing intricate surgery for hours at a time, so even small modifications can really help.

In one recent case, our company made an artificial knee implant specifically for a woman with restricted growth. We also had to design a new set of instruments so the surgeon could carry out the replacement surgery.

It’s crucial that we understand exactly what surgeons need, so we go to visit them and ideally go into the operating theatre with them. We’ll then put a team together and brainstorm some possible solutions, starting with sketches and then models based on simple materials like cardboard. After that, we’ll work up initial designs using our CAD (computer-assisted design) systems and print some 3D models – there’s nothing quite like having something physical in your hand. Once we think we’re heading in the right direction, we’ll run designs past the surgeons and get their feedback.

Testing is another crucial stage. Some testing is quite simple. We drop things repeatedly to make sure they don’t break and do a ‘bucket test’ where instruments are poured from one bucket into another - this is what happens when instruments are put in a giant dishwasher-like machine to be cleaned and sterilised. Other tests are more precise, like applying very specific forces to test the strength of devices. We also test the instruments in action on a range of artificial and animal bones (by-products of the meat industry). Because birds need very light bones, ostrich bones are an excellent model for human bones affected by trauma or osteoporosis, where bones lose a lot of their mass.

How did you end up in your current role?

I originally wanted to be a doctor – possibly the result of an unhealthy obsession with Grey’s Anatomy. But it dawned on me that a doctor’s working life was just too crazy for me. When the Paralympics were on television, I got fascinated by the prosthetics and devices they were using. I realised this could be another way to make a real difference to people’s lives.

Although there are bioengineering degree courses, I wanted to keep my options open so chose to study mechanical engineering. The course covered areas like automotive and aeronautical engineering, but I was always thinking about bioengineering applications. For my main project, I designed an artificial liver for people with liver disease, to take over the liver’s normal functions while their own organ regenerated.  

What’s the best thing about being an engineer?

I like the idea that the work I’m doing benefits people, both surgeons who are using the devices we’ve designed and, most importantly, their patients, which is something my company prides itself in. Surgeons send us videos showing us how they’re using their new instruments, and it’s very satisfying to see them in action when you’ve put so much time and effort into creating them.

It might take a year to design and produce a new instrument, and developing a completely new joint implant takes many years. What’s nice is you get lots of ‘mini-wins’ along the way. These can be small things, like when your calculations turn out to be correct, or your first 3D models feel right, or you get some good feedback from a surgeon you’re working with.

I’ve also been involved in with Engineers Without Borders, volunteers who use their engineering skills to help others overseas. At university, I helped develop educational workshops to enable communities in Ghana to maintain newly installed water and other engineering systems. I now help with a group called REMAP, who develop devices for people who can’t be helped by the NHS. Recently we created a splint for a DJ who had had a stroke, enabling him to use all the knobs and dials on his decks. It’s very rewarding seeing people benefit so quickly.

Can anyone become an engineer?

I was the first person to go into engineering in my family (though my younger brother has followed in my footsteps!). I occasionally found it hard not having family or other connections in engineering, like when I was applying for placements. And it can sometimes be discouraging when you don’t see people who look like you – engineering can look like a male-dominated field. I used to waitress when at university and it surprised me that people would still say ‘you don’t look like an engineer’ when I told them what I was studying. Things are changing, though. You need to maintain your self-confidence, and value the differences that you bring to the table.

Young people often just think about the technical aspects of engineering, the maths and the physics, but there’s much more to it than that. Communications skills are key – particularly listening skills: you need to understand what problem you are trying to solve for someone. Team-working is important too as you’ll never work on something on your own. Creativity is also central to problem-solving. Employers are also looking for these kinds of skills, not just technical knowledge.

There are huge opportunities in bioengineering, which covers many areas – medical imaging, artificial organs, prosthetics, diagnostics, robot-assisted surgery. The increasing use of ‘wearable’ technologies – devices that are constantly collecting data from patients – is very exciting.

It’s a field in which all kinds of science, technology and engineering come together – we recently hosted a visit from Formula 1 engineers who talked about how sensors integrated into car components continuously collect data during races. These could be embedded in implants to enable us to gather data to improve implant design. New materials are also being developed, and medical researchers are looking to engineers to help them come up with innovative and cost-effective new ways of delivering medicines. There’s never been a better time to get involved in the field.

What three things should young people know about engineering?

  • There are multiple routes into engineering; as well as the ‘academic’ route, apprenticeships are great for those who prefer the practical side, or you can develop your skills just by tinkering with things in the garage.
  • Communication skills are critical – engineering isn’t just about building technical knowledge.
  • Don’t think something has to be perfect first time – it never is! Getting it wrong can be just as useful as getting it right; it takes an idea off the table, and tells you something you didn’t know before.

The other advice I would give is to be persistent. Always keep going, when you’re trying to find the right placement or job, or you feel like you’re getting nowhere on a project – it’ll work out in the end.

Year of Engineering

Don’t think something has to be perfect first time – it never is! Getting it wrong can be just as useful as getting it right; it takes an idea off the table, and tells you something you didn’t know before.

Caroline WitherBioengineer, DePuy Synthes


Name: Caroline Wither

Employer: DePuy Synthes

Job title: Bioengineer

Role in a nutshell: Designing and developing surgical instruments to be used in joint replacements, such as hips or knees


  • 2009 - 2010: International Baccalaureate: Maths, English, Geography, Physics, Chemistry and French

  • 2009 - 2014: Master’s in Mechanical Engineering, University of Edinburgh

  • 2013 - 2014: Year abroad at McGill University, Canada, supported by the University of Edinburgh.

Career history:

  • 2014: Work experience in the SMART (Southeast Mobility and Rehabilitation Technology) Centre, NHS, Edinburgh

  • 2015: Junior Mechanical Engineer at Touch Bionics as part of a semester in industry, Edinburgh

  • 2016 - 2018: Graduate Engineer at DePuy Synthes (two-year rotational programme moving through four departments)

  • 2016 - 2018: Bioengineer, Made To Order Instruments, DePuy Synthes.

Awards and accolades:

  • 2016: Fredric Barnes Waldron IMechE Prize

  • 2013: Horsburgh Prize for Mathematics

  • 2012: Certificate of Merit for Industrial Management

Interests outside engineering:
Hiking, climbing and travelling