Session: Research Posters

Paper Number: 173893

Scalable Manufacturing of Biodegradable Capacitors and Resistors for Sustainable Electronics 

The reliance on single-use electronic sensors and components in modern devices is leading to increasing volumes of electronic waste. This compounds with the reliance on metal-based materials like silver, copper, and gold that are non-degradeable and energy intensive. This project presents an additive manufacturing approach using pneumatic extrusion to fabricate biocompatible and biodegradable capacitors and resistors as a potential solution to mitigate this issue. The primary objective is to develop and utilize functional inks derived from sustainable and scalable materials that can replace conventional non-degradable components, thereby reducing environmental impact while enabling Scalable manufacturing without utilizing materials from mining.

Utilizing a Nordson EFD pneumatic extrusion system electronic components can be printed while operating within a pressure range of 0–90 psi. Three distinct ink formulations were developed to fabricate conductors, dielectrics, and resistors. A silver nanoparticle-based ink was used for printing the electrodes, while two dielectric inks were formulated: (1) barium titanate nanopowder suspended in glycerol, and (2) biochar blended with glycerol and xanthan gum. The biochar-based ink, derived from biomass, introduces a biodegradable alternative to conventional ceramic or polymer dielectrics. For resistive elements, a carbon-based ink was developed using graphene, glycerol, and xanthan gum. This ink demonstrated tunable resistivity, with values decreasing from 25 Ω/mm at 200 °C to 11.5 Ω/mm at 300 °C, indicating thermal control can enable varying resistance functionality. Resistors were printed with fixed ink composition and varying lengths, allowing precise resistance tuning based on geometry alone. Capacitors were printed using a parallel plate architecture with alternating silver and dielectric layers ( Metal- Insulator- Metal). The first layer of silver required complete drying before depositing high-temperature dielectrics to avoid deformation of the surface via boiling. The barium titanate capacitors exhibited an average capacitance of ~85 pF at 9.4 MHz for a 4 mm² area, while the biochar-based devices yielded ~22.9 pF at 9.5 MHz. To assess repeatability and scalability, 10 capacitors and 30 resistors were fabricated. The project highlights the limitations of current sensor and component manufacturing practices, which often involve non-renewable, non-degradable, and mined materials like silver. In contrast, the introduction of inks based on biochar and graphene offers a path toward more sustainable and biodegradable electronics. Although silver is still used in this work for conductive electrodes, future efforts will explore carbon-based alternatives to completely eliminate non-degradable metals.

In conclusion, this work demonstrates that extrusion-based additive manufacturing can be used to produce capacitors and resistors with biodegradable materials suitable for scalable applications. This addresses both the technical and environmental challenges posed by the widespread deployment of single-use electronics and sensors. With further optimization, this method could support the development of next-generation sustainable electronics for wearable, environmental, and IoT applications.

Presenting Author: Jacob Farrell Boise State University

Presenting Author Biography: A student at Louisiana Tech university, Jacob Farrell is pursuing a career in mechanical engineering. Experienced with additive manufacturing through two undergraduate research experiences, he uses this knowledge to further develop other skills within the mechanical engineering curriculum.

Authors:

Jacob Farrell Boise State University