Durable and wear-resistant bar stock for finger prosthesis

• What was needed: iglidur ® J plain bearing
• Requirements: Load capacity, reliability in the tightest of spaces, freedom from lubricants and precision
• Industry: Prosthetics
• Success for the customer: A maintenance-free prosthesis solution for everyday use

Hand prostheses are becoming increasingly mobile, delicate and functional and are thus becoming more and more similar to their human counterparts. For people who have to live with the loss of individual fingers or part of the hand, there has been no satisfactory prosthetic solution until now. The VINCENT finger closes this gap and opens up new possibilities for those affected. The company VINCENT Systems GmbH manufactures fingers for everyday movement and thus offers prosthesis wearers a way of coping better with everyday life.
Particularly in the area of this very precise and sometimes heavily loaded application, clearance and wear-free transmission of forces is of great importance. The special requirements are primarily due to point loads that are triggered by rapid and impulse-like or oscillating movements.
A hand prosthesis must also be able to cope in sometimes very harsh environments and remain fully functional in dirty or wet application areas. Finally, a solution had to be found that also functions in the smallest possible installation space and can be realised with an aesthetically pleasing design.

This prosthesis is an electrically powered finger. The base joint of the finger is moved directly via a geared motor, while the centre joint is guided by a spring-loaded connection. All axes involved in this movement are now supported by our plastic bushings made of the material iglidur® J. A total of 8 such bearings are integrated in one finger. The control system of the prosthesis is controlled by muscle signals that are transmitted to a microcontroller. The energy supply is provided by 2 lithium-ion batteries.
The bearings, which are milled from iglidur® J bar stock, ensure corrosion resistance and a low wear rate. For use on the body, however, freedom from lubricants and freedom from maintenance are also two important criteria that the plastic bearings fulfil. They also reduce the transmission of noise from the motor to neighbouring joints in order to avoid complications. However, the bearing solution also fulfils the possible use in dirty or wet application areas with a long service life.