Desenvolvimento de termosensores nanoestruturados impressos em 3D

Abstract

The market for temperature sensors and other related devices has grown significantly in recent years. It is estimated that there will be an annual growth rate of 11% between 2019 and 2026. This growth has sparked interest in studies focusing on alternative nanosensors that offer better portability, sustainability, and may contribute to achieving the Sustainable Development Goals (SDGs). This work presents the development of four sensors based on Poly (lactic acid) - PLA and Carbon Nanotubes - CNTs, produced using additive manufacturing. These sensors are designed for monitoring body temperature (35 to 45ºC) and cold room temperatures (5°C to -40°C), covering an active area of 15cm2. One of these sensors was developed using only PLA as a control sample, while the others were nanostructured by adding two different types of inks containing CNTs. The synthesis of these sensors was performed through 3D printing using Fused Deposition Modeling (FDM) technology, with a specific synthesis method for each sensor. Through morphological, vibrational, and electrical characterizations, the devices/sensors exhibited thermoresistive and thermoelectric responses to temperature variations. Electronic microscopy and vibrational Raman spectroscopy analyses of the nanocomposite samples revealed the successful incorporation of CNTs into the PLA matrix, as evident from their characteristic vibrational spectra. The sensors demonstrated a Seebeck coefficient of 1.33μV/K under temperature gradients of 300K, and a maximum thermoresistive response of -4.35± 0.15% at approximately 45°C. Thus, such developed devices exhibited the behavior of thermistors and thermocouples, making them a promising alternative for implementation in cold rooms and Home Health systems.