High performance of metallic thin films for resistance temperature devices with antimicrobial properties

• Published in: Sensors (Basel, Switzerland) Switzerland), 2022-10, Vol.22 (19), p.1-10
• Main Authors: Souza, Arthur L. R., Correa, Marcio A., Bohn, Felipe, Castro, Helder, Fernandes, Margarida Maria Macedo, Vaz, F., Ferreira, Armando José Barros
• Format: Article
• Language: English
• Subjects: Ambient temperature; Antiinfectives and antibacterials; Antimicrobial; Antimicrobial agents; Bacteria; Bacterial infections; Control equipment; E coli; Electric waves; Electromagnetic radiation; Electromagnetic waves; Magnetron sputtering; R&D; Radiation; Research & development; Room temperature; Scanning electron microscopy; Science & Technology; Sensors; Stoichiometry; Temperature sensors; Thin films; titanium-copper; Universal Serial Bus
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s22197665

Titanium-copper alloy films with stoichiometry given by Ti 1 − x Cu x were produced by magnetron co-sputtering technique and analyzed in order to explore the suitability of the films to be applied as resistive temperature sensors with antimicrobial properties. For that, the copper (Cu) amount in the films was varied by applying different DC currents to the source during the deposition in order to change the Cu concentration. As a result, the samples showed excellent thermoresistivity linearity and stability for temperatures in the range between room temperature to 110 °C. The sample concentration of Ti 0.70 Cu 0.30 has better characteristics to act as RTD, especially the α T C R of 1990 × 10 − 6 ° C − 1 . The antimicrobial properties of the Ti 1 − x Cu x films were analyzed by exposing the films to the bacterias S. aureus and E. coli , and comparing them with bare Ti and Cu films that underwent the same protocol. The Ti 1 − x Cu x thin films showed bactericidal effects, by log 10 reduction for both bacteria, irrespective of the Cu concentrations. As a test of concept, the selected sample was subjected to 160 h reacting to variations in ambient temperature, presenting results similar to a commercial temperature sensor. Therefore, these Ti 1 − x Cu x thin films become excellent antimicrobial candidates to act as temperature sensors in advanced coating systems. This work was supported by FCT-UIDB/04650/2020. A.L.R.S. thanks CAPES (88887.572905 /2020-00) and CNPq. M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18-C.F. (2) junior researcher contract).