In-situ laser sintering for the fabrication of fully 3D printed electronics composed of elastomeric materials

In-situ laser sintering can be used to locally sinter conductive inks in an uninterrupted process, enabling the embedding of printed electronics within 3D printed structures. In this work we apply a laser sintering method to create highly conductive silver features (50-125 mu Omega cm) on top of and embedded within thermosensitive polymers printed by fused deposition modelling (FDM). We exploit this method to locally sinter silver inks deposited by direct ink writing (DIW) without external processing. Furthermore, we perform this while thermally preserving the 3D printed thermoplastic polyurethane (TPU) substrate which has a low glass transition temperature. By analyzing the effect of the process for both small and large shapes of conductive features, we show the importance of the transmitted power and sintering time. Lastly, we apply the developed method to produce flexible conductors and sensors. These include pressure and bending sensors that could find their way into cost-effective and customized soft electronic devices.

Automated summary

This study demonstrates the use of in-situ laser sintering to create conductive silver features within 3D printed structures, showing the importance of transmitted power and sintering time for different shapes of conductive features. The developed method successfully produces flexible conductors and sensors, which could potentially be integrated into cost-effective and customized soft electronic devices.