title: Direct-write fabrication of freestanding nanocomposite strain sensors.
abstract: This paper deals with the design and microfabrication of two three-dimensional (3D) freestanding patterned strain sensors made of single-walled carbon nanotube (SWCNT) nanocomposites with the ultraviolet-assisted direct-write (UV-DW) technique. The first sensor consisted of three nanocomposite microfibers suspended between two rectangular epoxy pads. The flexibility of the UV-DW technique enables the sensor and its housing to be manufactured in one monolithic structure. The second sensor was composed of a nanocomposite network consisting of four parallel microsprings, which demonstrates the high capability of the technique when compared to conventional photolithographic technologies. The performances of the sensors were assessed under tension and compression, respectively. The sensors' sensitivities were evaluated by correlating their measured resistivities to the applied displacements/strains. Electrical conductivity measurements revealed that the manufactured sensors are highly sensitive to small mechanical disturbances, especially for lower nanotube loadings when compared to traditional metallic or nanocomposite films. The present manufacturing method offers a new perspective for manufacturing highly sensitive 3D freestanding microstructured sensors.
authors.affiliation: Laboratory for Multiscale Mechanics, Center for Applied Research on Polymers, École Polytechnique de Montreal, succ. Centre-Ville, Montreal, QC, Canada.
authors.forename: Rouhollah Dermanaki
authors.initials: RD
authors.lastname: Farahani
authors.forename: Hamid
authors.initials: H
authors.lastname: Dalir
authors.forename: Vincent
authors.initials: V
authors.lastname: Le Borgne
authors.forename: Loick A
authors.initials: LA
authors.lastname: Gautier
authors.forename: My Ali
authors.initials: MA
authors.lastname: El Khakani
authors.forename: Martin
authors.initials: M
authors.lastname: Lévesque
authors.forename: Daniel
authors.initials: D
authors.lastname: Therriault
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D055119:Elastic Modulus; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D036103:Nanotechnology / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013314:Stress, Mechanical; D014159:Transducers
chemical_list: D037742:Nanotubes, Carbon