Cryosurgery employs extremely low temperatures to destroy abnormal or cancerous tissue. Conventional systems use cryogenic fluids like liquid nitrogen or argon, which pose challenges in handling, cost, and precise temperature control. This study explores thermoelectric (TE) cooling using the Peltier effect as an efficient alternative. A numerical optimization of multi-stage TE coolers using bismuth telluride (Bi₂Te₃) is performed through finite element analysis in COMSOL Multiphysics. Results show that the optimized multi-stage TE system achieves a minimum temperature of −70 °C, a 90 K temperature difference, and 4.0 W cooling power—outperforming single-stage (SS) systems with a maximum ΔT of 73.27 K. The study also investigates the effects of material properties, current density, and geometry on performance. An optimized multi-stage (MS) configuration improves cooling efficiency by 22.8%, demonstrating the potential of TE devices as compact, energy-efficient, and precise solutions for cryosurgical applications. Future work will explore advanced nanomaterials and hybrid systems to further improve performance in biomedical cooling.

Thermoelectric cooling (TEC) offers compact, reliable, and eco-friendly thermal management for biomedical and medical refrigeration applications. This numerical study compares SrTiO₃ and PbTe-based TEC modules using a fully coupled electro-thermal finite-element model. Performance metrics include temperature difference-current (ΔT-I), temperature difference-heat load (ΔT-Q), and coefficient of performance under varying operating conditions. Results show that the SrTiO₃ module achieves a maximum temperature difference of ΔTmax ≈ 65.48 K, surpassing PbTe ≈ 52-58 K under similar conditions. The SrTiO₃ module also exhibits a maximum cooling capacity of Qc,max ≈ 8.79 W at ΔT = 0 K. COP analysis reveals superior efficiency for SrTiO₃, reaching ≈ 1.1 at ΔT = 20 K, compared to PbTe < 0.6. Additionally, SrTiO₃ demonstrates enhanced thermal robustness, maintaining stable cooling under increasing heat loads. The superior performance of SrTiO₃ stems from its favorable transport properties (high electrical conductivity and moderate thermal conductivity), combined with non-toxicity, environmental compatibility, and thermal durability-advantages over toxic lead-based alternatives. These findings highlight SrTiO₃ strong potential for next-generation solid-state cooling in localized therapeutic devices, medical refrigeration, and biomedical thermal management. Nomenclature: