Student designs DIY finger exoskeleton

As part of his Master’s Honours Programme in High Tech Systems and Materials, University of Groningen Biomedical Engineering student Sander Hekkelman designed an ‘exoskeleton’ that can support a finger. It could, for example, be used by people who have reduced grip strength following a stroke. The exoskeleton was inspired by the DIY science exhibition ‘Beyond the Lab’ at the University Museum.

Hekkelman designed the exoskeleton as part of the Master’s Honours Programme in High Tech Systems and Materials. This programme adds an additional 20 ECTS to the Master’s degree programme, in his case Biomedical Engineering. ‘Part of this Honours Programme is setting up an individual Master’s work project in collaboration with a client, if applicable,’ says Hekkelman. His client was Science LinX, the science centre at the Faculty of Science and Engineering. They asked for a design that would fit in with the ‘Beyond the Lab’ exhibition that focuses on DIY science.

Grip

Hekkelman decided to design an exoskeleton to help people with reduced grip strength. ‘For reasons of time, my design is limited to just one finger, but it could easily be extended.’ The final product is a glove with a force detector at the fingertip that measures the force exerted by the finger. ‘When the force is above a lower limit, a servomotor kicks in to increase the grip force via a cable and the exoskeleton,’ explains Hekkelman. The sensor keeps the force below an upper limit.

Arduino

The exoskeleton can be produced by a 3D printer, although other production methods are also possible. The servomotor can be bought for between 10 and 30 euros. An Arduino controller is used to operate the system. All in all, the entire setup as built by Hekkelman costs less than 100 euros. ‘The prototype works, but it will need some further fine-tuning, which I couldn’t do within the time available.’

Meanwhile, Hekkelman is working at the Medical Centre Leeuwarden on a different project. ‘This is for my graduation. I am working on a machine that will scan the hands of patients with rheumatoid arthritis and that will detect active inflammation.’ He hopes to finish his Master’s programme this summer.

You can read the builing instructions for the exoskeleton in the final report submitted by Sander Hekkelman.