Cost-effective PEDOT:PSS Temperature Sensors Inkjetted on a Bendable Substrate by a Consumer Printer

Area of Science:

• Materials Science
• Sensor Technology
• Printed Electronics

Background:

• Development of flexible electronic sensors is crucial for wearable and IoT applications.
• Inkjet printing offers a cost-effective and scalable fabrication method for electronic devices.
• Polymer-based inks like PEDOT:PSS are promising for printable sensing layers.

Purpose of the Study:

• To report a fabrication protocol for fully inkjet-printed temperature sensors on a bendable polyethylene terephthalate (PET) substrate.
• To investigate the effect of interdigitated electrode (IDE) dimensions and post-deposition treatments on sensor performance.
• To evaluate the temperature and humidity response of the fabricated sensors.

Main Methods:

• Utilized commercially available Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and silver nanoparticle (AgNP) inks.
• Employed a cost-effective consumer printer with standard cartridges for inkjet printing.
• Fabricated sensors with varying IDE dimensions (150 µm and 200 µm spacing) and tested post-deposition treatments.
• Characterized sensor response to temperature (20-70 °C) and relative humidity (20-90% RH).

Main Results:

• Successfully fabricated fully inkjet-printed temperature sensors on PET substrates.
• Sensor modules with 200 µm electrode spacing exhibited 1.8 to 2.2 times higher thermal sensitivity compared to those with 150 µm spacing.
• All fabricated sensors demonstrated high linearity towards temperature.
• Achieved sensor performance comparable to existing state-of-the-art temperature sensors.

Conclusions:

• Inkjet printing provides a viable method for producing high-performance, flexible temperature sensors.
• Optimizing IDE dimensions, particularly electrode spacing, significantly impacts thermal sensitivity.
• The developed sensors show potential for applications requiring low-cost, flexible temperature monitoring.