[P007] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P04-595] A Biodegradable Microalgae-Derived Flexible Biosensor for Humidity and Physiological Monitoring toward Sustainable Wearable Electronics

○Shang Shiuan Yu¹, Hsien Yin Huang¹, Chun Yen Chen^1,2,3,4 (1. University Center for Bioscience and Biotechnology, NCKU (Taiwan), 2. Department of Biomedical Engineering, NCKU (Taiwan), 3. Department of Biotechnology and Bioindustry Sciences, NCKU (Taiwan), 4. Research Center for Circular Economy, NCKU (Taiwan))

Keywords:

Microalgae-derived biomaterials,Biodegradable sensors,Wearable biosensing,Biocompatible materials

The development of eco-friendly and biocompatible materials for next-generation biomedical devices has attracted increasing attention. In this study, a flexible and biodegradable sensing platform was fabricated from a bio-derived microalgae matrix rich in naturally occurring antioxidant compounds. Following extraction of bioactive components, the residual algal biomass was blended with starch, sodium alginate, and glycerol to form a flexible biopolymer substrate via a green fabrication process. The substrate was subsequently coated with PEDOT:PSS to produce a sustainable conductive film suitable for wearable physiological monitoring. Electrical characterization showed a surface resistance of 780 ± 32 Ω/sq. Humidity sensing tests revealed a resistance change of 15.32–21.5% under relative humidity levels of 60–90% (±3.0%), demonstrating stable and sensitive responses suitable for skin hydration, sweat monitoring, and respiratory moisture detection. Mechanical durability tests confirmed stable conductivity after 75 bending cycles, supporting suitability for skin-interfaced electronics. Film extracts exhibited measurable antioxidant activity (DPPH radical scavenging: 29.5% at 10 mg/mL, after background correction), supporting the biocompatibility potential of the microalgae-derived matrix for skin-interfaced wearable sensing. The biodegradable substrate showed visible degradation after 13 days and 54.3% decomposition after 30 days in soil burial tests, markedly outperforming petrochemical-based substrates. By utilizing renewable algal residues, this approach contributes to reducing electronic waste and advancing sustainable wearable electronics. Overall, this work presents a green and cost-effective strategy for transforming microalgae residues into flexible, conductive, and biodegradable biosensors with promising applications in physiological monitoring, environmental sensing, and next-generation sustainable biomedical devices.