Inkjet-Printed Bio-Based Melanin Composite Humidity Sensor for Sustainable Electronics
Peter Krebsbach1,2, Mikel Rincón-Iglesias1,2,3, Manuel Pietsch1,2
1Light Technology Institute, Karlsruhe Institute of Technology, Engesserstr. 13, 76131 Karlsruhe, Germany.
ACS Applied Materials & Interfaces
|August 1, 2024
Summary
This study developed sustainable, inkjet-printed flexible humidity sensors using black soldier fly melanin. The biodegradable sensors offer fast response times and stable operation, addressing electronic waste challenges.
Area of Science:
- Materials Science
- Environmental Science
- Sensor Technology
Background:
- Electronic waste and unsustainable material sourcing pose significant environmental and ethical challenges.
- Current electronic components often utilize materials with problematic sourcing and end-of-life disposal issues.
- Developing sustainable alternatives for electronic components is crucial for mitigating environmental impact.
Purpose of the Study:
- To investigate the inkjet printing of flexible humidity sensors using biosourced and biodegradable materials.
- To enhance the sustainability of sensor fabrication processes.
- To create functional humidity sensors from waste-derived materials.
Main Methods:
- Optimization of an aqueous dispersion of black soldier fly melanin for inkjet printing.
- Deposition of melanin onto flexible substrates with interdigitated silver electrodes.
- Utilizing impedance spectroscopy to analyze sensor performance with additives like choline chloride.
Main Results:
- Inkjet-printed melanin sensors demonstrated enhanced conductivity and sensing performance with choline chloride.
- Achieved fast detection (0.8 ± 0.5 s) and recovery (0.8 ± 0.3 s) times.
- Observed a significant 170 ± 40-fold impedance decrease across a 30%-90% relative humidity range, with stable operation over 72 hours.
Conclusions:
- Inkjet printing of black soldier fly melanin offers a sustainable approach for flexible humidity sensors.
- The developed sensors exhibit excellent performance, fast response, and stability, suitable for various applications.
- The use of waste byproducts and focus on reusability/degradability enhance the sensor's environmental credentials for wearable and agricultural use.
