“Things rarely work straightaway”

From the university magazine Zett

Photographs: Reto Togni, Stefan Villiger

Published on

Author Léa Ermuth

Reto Togni studied industrial design at ZHdK and is now a postdoctoral researcher at ETH Zurich. In this interview, he talks about his relocation from Zurich to London, his research into a manual wheelchair steering system and working at the Design Technology Lab.

Léa Ermuth: How did you experience the transition from ZHdK to the Royal College of Art (RCA) and Imperial College London?

Reto Togni: My class consisted of 44 students from a wide range of disciplines—from art through architecture to computer science. I was impressed by the variety of methods and topics that were applied and discussed in this interdisciplinary setting. One key insight was realizing that as an industrial designer I possess intuitive skills. While mechanical engineers relied on complex simulations, I could count on my trained sense of proportion. I developed this skill, which many others completely lack, as an industrial design student in ZHdK’s workshops. It has proven invaluable in practice.

You are researching a wheelchair steering system at ETH Zurich. How exactly does the system work?

Well, it’s a mechanical manual wheelchair. Conventional manual wheelchairs work similarly to a shopping trolley or pushchair. The “loose” front wheels follow the wheelchair’s movement trajectory, while the “fixed” rear wheels determine the direction. The wheels are independent, so the trajectory is determined by the varying speeds of the rear wheels. If both wheels turn at the same speed, the chair moves in a straight line; if one wheel turns more slowly than the other, the chair curves. The problem is that controlling the movement and direction basically always means braking. If you want to turn, it’s like steering a Davos sledge: you put your foot in the snow to make the turn, but slow down as a result. This is particularly problematic when travelling straight ahead, as surfaces are rarely flat. Outdoors, you usually have a drainage gradient. This is particularly evident on pavements. Even if the cross slope is often only 2 degrees, this means that the upper hand applies the brakes while the lower hand pushes. This is relevant because long-term wheelchair users often develop shoulder problems. In my approach, a steering system is attached to the wheelchair. Similar to a car’s steering wheel, it enables users to determine their direction without having to brake.

What are the advantages of your steering system compared to conventional manual wheelchairs?

The backrest functions as a steering wheel: if you lean to the right, the wheelchair moves to the right, and vice versa. This is particularly important on footpaths: because if you sit upright, the wheelchair moves straight ahead, regardless of the surface. Our laboratory tests show that our steering system requires only half as much energy for the same test course as the conventional system. Many people find this more pleasant, as everything feels more fluid and dynamic. Users particularly appreciate the fact that they can steer the chair with one hand by using their upper body to determine the direction. For example, you can hold a cup of coffee and drive at the same time.

Researching your wheelchair steering system always brings you back to ZHdK’s Industrial Design programme. For example, your wheelchair steering system was applied in a degree thesis about a basketball wheelchair. Are you involved in any other diploma projects?

One project is developing a customizable design for a seatshell backrest. A wheelchair presents a customization challenge. You have different seat heights at the back and front, as well as various seat widths and depths. There are also different backrest angles and heights, wheel diameters and lower-leg lengths. If you start combining these variables, you quickly end up with well over 1,000 variants of the same product. So a wheelchair really is a customized product.

Is that one reason why wheelchairs are so expensive?

Yes, that’s the major cost driver. One of the potential problems of my research might be the introduction of new parameters, such as the reaction speed of the steering device, the radius of the tightest possible turn or the degree of user support. If we add these parameters, the number of variants increases from 1,500 to 27,000, which is not economically viable. The degree project that I just mentioned is seeking to integrate the mechanics and steering into a standardized frame. While this remains the same, the seat can be customized, allowing for all kinds of adaptations.

Working iteratively and prototype-based testing are essential to making improvements.

Reto Togni
So only one part can be customized rather than the entire wheelchair.

Exactly, I sometimes look at the spare parts catalogues of wheelchair manufacturers and ask myself: Why are there so many different variants for each individual part? It’s incredibly complicated and drives up costs. My steering system will only be successful if the process is simplified—otherwise, everything will simply become more complicated.

Will the project results be used for your ETH research?

I hope so. It would be great to have results that we could build on.

Which methods or processes that you learned at ZHdK are you using at ETH?

Working iteratively and prototype-based testing are essential to making improvements. Failing quickly and constructing prototypes are equally indispensable. It’s more effective to promptly build three models than to keep planning for a long time and then produce a model that doesn’t work. My design experience has shown me that things rarely work straightaway.

That’s also my experience: the design process always involves taking two steps forward and one step back.

You also learn to anticipate that. If failure is foreseeable, you try to provoke it because you’ll gain valuable insights at the first attempt and learn something new.

Has any ZHdK project or experience proven decisive for your future career?

Working at the Design Technology Lab was certainly formative. When the lab was founded, the vision was to create a place where mechanical engineering and industrial design could work side by side. If you ask mechanical engineers about product development, they refer to engineering, that is, requirements analysis, conceptualization, morphology, elaboration, simulation and so on. Design only comes into play at the end of the process: the logo needs to be positioned and the colours chosen. Designers, on the other hand, first see the concept, then the models and so on, and ultimately the engineers have to make the product work. Actually, both approaches are incomplete. It would be an advantage if they ran in parallel, that is, started and ended at the same time. This is the basic idea behind the tandem projects being pursued at the Design Technology Lab. ZHdK industrial design students work together with ETH mechanical engineering students. The projects are hugely beneficial for both sides.

What significance does ZHdK have for driving innovation in design?

A few years ago, the Tages-Anzeiger wrote about ZHdK’s degree exhibition: “A goldmine of good ideas.” That description still fits. ZHdK is a source of fresh impetus in design.