D-SENSE

Digital Manufacturing of 3D-Printed Wearable Sensors

Recently 3D-printing has made strong progress and is applied to the fabrication of various structural elements. One of the key challenges for the full exploitation of the potential of the technology is to integrate the printing of functional layers into the process chain. Implementation of sensing components by printing during their fabrication would make the 3D-printed objects smarter. At the same time, sensors production would benefit – thanks to their digital manufacturing in the 3rd dimension – from customization, self-packaging and better integration into products.

The project aims to solve one key challenge of integration of sensors into products: Enabling the integration of functional sensing layers into the fabrication process of 3D-printed objects. The objective is to apply digital printing of functional and structural inks targeting the whole processing in a single tool.

D-SENSE project overview, Source: LMTS, EPFL

Scope of Research Activities
Materials development

Development of 3D printing inks with optimized rheological properties
Development of cellulose-based composite inks for wearable applications
Development of functional inks for printing sensors and transfer of passive/silicon electronics

Process development

Printing of electrical conductors on complex 3D printed soft structures
Printing physical resistive, capacitive and triboelectric sensors in soft 3D printed parts
Methods to integrate passive and silicon components in soft 3D printed parts

Characterization and testing

3D-printed biocompatible and breathable cellulose composite elastomers
Printed mechanical sensors in soft 3D printed parts
Knee pad with integrated sensors compatible with wireless communication
Knee pad performance on the human body

Key Technical Problems to Solve

Processing of conformal polymer composites with locally controlled mechanical properties
Processing of electrical conductors on temperature sensitive polymeric composite materials
Morphological, adhesion and electrical properties for multi-layer stacks on variable surface chemistry, roughness and topography
Process compatibility: printing and curing/sintering of functional and structural materials
Process integration of printed functional materials and silicon components within 3D-printed materials
Electrical interconnections of multi-layer stack of printed sensors, silicon components, antenna, battery
Robustness and reliability of the functional 3D-printed soft wearables under mechanical deformation

Demonstrator

Knee pad that is equipped with integrated mechanical sensors, that is compatible with wireless communication and that will be in perfect contact with the skin of the patient

Linked Scientific Publications

van Dommelen, R., R. I. Haque, O. Chandran, S. Lani and D. Briand (2021). "In-situ laser sintering for the fabrication of fully 3D printed electronics composed of elastomeric materials." Flexible and Printed Electronics 6(4): 045003.

Leading Principal Investigator

Dr. Danick Briand
Soft Transducers Laboratory (LMTS), EPFL

Project Consortium

Prof. Dr. André Studart
Complex Materials Laboratory, ETH Zürich
Dr. Gilberto de Freitas Sequeira
Laboratory for Applied Wood Materials, Empa
Dr. Sébastien Lani
Micro & Nano Systems, CSEM
Prof. Dr. Brigitte Jolles-Haeberli
Swiss Biomotion Laboratory, CHUV
(University Hospital in Lausanne)