Polyaniline-based Unicouple Thermoelectric Generator: Simulation and Performance Insights for Flexible Energy Harvesting

Abstract

Flexible thermoelectric generators (TEGs) based on conducting polymers present a promising route for harvesting low-grade waste heat in wearable and Internet of Things (IoT) applications. This work simulates a polyaniline (PANI)-based unicouple using experimentally realistic doped-PANI parameters within a one-dimensional coupled thermoelectric model implemented in MATLAB. For a single leg (length L= 1 mm, area A=1 mm²) under a temperature gradient of ΔT = 75 K, the model predicts an open-circuit voltage of 3.75 mV, maximum output power of 3.3 μW, efficiency of approximately 0.15%, and a figure of merit ZT ≈0.15 (Seebeck coefficient S = 50 μV K⁻¹, electrical conductivity σ = 1000 S m⁻¹, thermal conductivity κ = 0.3 W m⁻¹ K⁻¹). Scaling to a 100-leg module yields 0.375 V and 0.33 mW at matched load, with load-optimization confirming peak power near R-L ≈ internal + contact resistance (≈1 Ω). Incorporating simulated graphene fillers (σ ↑ to 1500 S m⁻¹, κ ↑ to 0.4 W m⁻¹ K⁻¹) enhances power output by approximately25%. These modest outputs align with benchmarks for pure or lightly composite PANI systems, highlighting advantages in flexibility, low cost, and processability compared to inorganic counterparts. Recent advances in PANI nanocomposites—such as multilayer PEDOT: PSS/CNT/rGO hybrids and oriented CNT/PANI fibers—indicate pathways toward ZT >0.3 and improved device-level performance for practical μW-scale energy harvesting.