Laser Sintering of Printed Silver Thin Films for Fabrication of Strain Sensor Directly on a Structure (Preprint)
Abstract
Piezoresistive strain sensors, commonly known as resistance strain gauge, have many important applications. In this work, an alternative method to fabricatepiezoresistive strain sensors directly on the structure of interest is demonstrated using a particle-free silver ink as the sensing material. The sensing material is first printed as a rectangular film on the structure of interest and a conductive serpentine pattern is generated by selective laser sintering. Only the material exposed to the focused laser is sintered and becomes conductive. The rest is washed-off by 1-dodecene solvent, leaving only the serpentine pattern, which serves as the piezoresistive strain sensor. This alternative method eliminates the need for a carrier or backing substrate and thus improves the mechanical coupling between the sensing material and the structure of interest. It also removes reinforcement effect due to the stiffness of the carrier substrate. Results from electrical characterization revealed that laser sintering power is a crucial parameter that influences fundamental properties of the sensing material such as electrical conductivity and work function. In addition, it was observed that there exists an optimum laser sintering power that results in a maximum gauge factor (GF). For strain sensors, the GF is the most important parameter because it is the measure of sensor sensitivity. When the particle-free silver ink was printed as a serpentine pattern followed by thermal sintering on a hot plate, a lower GF was measured. This shows that the alternative method to fabricate piezoresistivestrain sensors is more attractive than printing the serpentine pattern then thermally sintering it.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2022
- Accession Number
- AD1181423
Entities
People
- Carrie Bartsch
- Emily Heckman
- Laura Davidson
- Roberto Aga
Organizations
- Air Force Research Laboratory
- KBR, Inc.