Study on the formulation of green/eco thick film piezo resistive paste for strain gauge application

Abstract

Thick film piezo resistors, such as strain gauges fabricated using screen printing technology, are widely used for pressure-sensing applications. This paper reports the study of RuO2-based piezoresistive pastes formulation using lead-free glass frits for their potential application for strain gauges. Thermal analysis (TG/DTA) of the prepared glass frit and piezo resistor paste composition was performed to understand the thermal behavior of the paste and the glass transition temperature of the glass frit. The XRD patterns of the films revealed no variation in the conductive phase concentration concerning the firing temperature. SEM analysis of the glass frit powders and the RuO2 powder show submicron-sized agglomerated particles. Electrical measurements showed that the samples fired at 750 ​°C have high gauge factor values (GFL ​= ​18.08, GFT= 12.50), indicating that this is the most suitable firing temperature to achieve the high gauge factor in the present study.

Keywords

• RuO2
• Piezo resistor
• Thick film
• Lead-free glass frit
• Gauge factor