title: An ionic liquid based strain sensor for large displacement measurement.
abstract: A robust and low cost ionic liquid based strain sensor is fabricated for high strain measurements in biomedical applications (up to 40 % and higher). A tubular 5 mm long silicone microchannel with an inner diameter of 310 µm and an outer diameter of 650 µm is filled with an ionic liquid. Three ionic liquids have been investigated: 1-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide, ethylammonium nitrate and cholinium ethanoate. When the channel is axially stretched, geometrical deformations change the electrical impedance of the liquid channel. The sensors display a linear response and low hysteresis with an average gauge factors of 1.99 for strains up to 40 %. Additionally, to fix the sensor by surgical stitching to soft biological tissue, a sensor with tube clamps consisting of photopatternable SU-8 epoxy-based resin is proposed.
authors.affiliation: KU Leuven, ESAT-MICAS, Kasteelpark Arenberg 10, 3001, Heverlee, Belgium. grim.keulemans@esat.kuleuven.be.
authors.forename: Grim
authors.identifier: 0000-0002-9520-6516
authors.initials: G
authors.lastname: Keulemans
authors.affiliation: KU Leuven, ESAT-MICAS, Kasteelpark Arenberg 10, 3001, Heverlee, Belgium.
authors.forename: Frederik
authors.initials: F
authors.lastname: Ceyssens
authors.affiliation: KU Leuven, ESAT-MICAS, Kasteelpark Arenberg 10, 3001, Heverlee, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Puers
mesh_terms: D003365:Costs and Cost Analysis; D017097:Electric Impedance; D052578:Ionic Liquids / Q000737:chemistry; D055616:Microtechnology / Q000295:instrumentation*; D009861:Onium Compounds / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D013314:Stress, Mechanical
chemical_list: D052578:Ionic Liquids; D009861:Onium Compounds; D011759:Pyrrolidines; C000607438:1-butyl-1-methylpyrrolidinium
keywords: 1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide; Cholinium ethanoate; Ethylammonium nitrate; Ionic liquid; Large displacement strain sensor