Soft Skin Elongation Sensors

Ramirez D Morgado, R Jackson, Catherine Holloway, P Smitham, D Hill
in European Conference of the International Federation for Medical and Biological Engineering (MBEC 2014), Conference paper (text), Dubrovnik, Croatia


Current advances in wearable flexible and elastic sensors show important applications for monitoring skin health and safety where technology is in contact with the human body, such as with assistive technology. However, the availability of these advances has been shadowed by patented techniques and often difficult to reproduce fabrication procedures. Open source knowledge and data acquisition platforms such as Arduino have recently opened the opportunity to transfer technology into low resource settings. This accelerates and facilitates the fabrication and application of tools that can have a significant impact in improving the performance of assistive technology. Similarly, 3D printing offers further opportunities such as being able to print orthoses parts anywhere in the world. Therefore it is desirable to use these "facilitators of knowledge transfer" to create soft skin elongation sensors that will aid in the understanding of the skin-technology interface in settings where this type of technology will otherwise be unaffordable, too complicated to manufacture or impossible to use due to patent infringement issues.
The aim of this study was to test various techniques and materials in order to fabricate a soft skin elongation sensor with a flexible connection. 3D printed moulds and a selection of conductive threads, yarns and fabrics were employed to produce and test skin elongation sensor prototypes on thin biocompatible silicon bodies that could be temporarily glued to the human skin. These sensors were also designed to have a flexible connection and be able to communicate to a computer through Arduino. The performance of various soft skin elongation sensors prototypes is presented. These sensors will be useful for characterizing comfort and safe skin stretching where the skin interfaces with technology such as with prostheses, orthoses and exoskeleton technology. Similarly, these skin elongation sensors could be used in humanoid robots for low cost tactile sensing.