Gas Sensors Based on Locally Heated Multiwall Carbon Nanotubes Decorated with Metal Nanoparticles

Autor(es)

Savu, R. ; Silveira, J. V. ; Alaferdov, A. ; Joanni, E. ; Gobbi, A. L. ; Canesqui, M. A. ; de Lara, D. S. ; Souza Filho, A. G. ; Moshkalev, S. A.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF SENSORS; v. 2015, p. 8-pg., 2015-01-01.

Resumo

We report the design and fabrication of microreactors and sensors based on metal nanoparticle-decorated carbon nanotubes. Titanium adhesion layers and gold films were sputtered onto Si/SiO2 substrates for obtaining the electrical contacts. The gold layers were electrochemically thickened until 1 mu m and the electrodes were patterned using photolithography and wet chemical etching. Before the dielectrophoretic deposition of the nanotubes, a gap 1 mu m wide and 5 mu m. deep was milled in the middle of the metallic line by focused ion beam, allowing the fabrication of sensors based on suspended nanotubes bridging the electrodes. Subsequently, the sputtering technique was used for decorating the nanotubes with metallic nanoparticles. In order to test the as-obtained sensors, microreactors (100 mu L volume) were machined from a single Kovar piece, being equipped with electrical connections and 1/4 '' Swagelok-compatible gas inlet and outlets for controlling the atmosphere in the testing chamber. The sensors, electrically connected to the contact pins by wire-bonding, were tested in the 10(-5) to 10(-2) W working power interval using oxygen as target gas. The small chamber volume allowed the measurement of fast characteristic times (response/recovery), with the sensors showing good sensitivity. (AU)

• Processo FAPESP: 09/14600-4 - Reatores e sensores de gases baseados em nanotubos de carbono decorados com nanopartículas
• Beneficiário: Raluca Savu
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado