title: Oxygen sensing using microrobots.
abstract: We present a luminescence oxygen sensor incorporated in a wireless intraocular microrobot for minimally-invasive diagnosis. This microrobot can be accurately controlled in the intraocular cavity by applying magnetic fields. The microrobot consists of a magnetic body susceptible to magnetic fields and a sensor coating. This coating embodies Pt(II) octaethylporphine (PtOEP) dyes as the luminescence material and polystyrene as a supporting matrix, and it can be wirelessly excited and read out by optical means. The sensor works based on quenching of luminescence in the presence of oxygen. The excitation and emission spectrum, response time, and oxygen sensitivity of the sensor were characterized using a spectrometer. A custom device was designed and built to use this sensor for intraocular measurements with the microrobot. Due to the intrinsic nature of luminescence lifetimes, a frequency-domain lifetime measurement approach was employed. An alternative sensor implementation using poly(styrene-co-maleic anhydride) (PS-MA) and PtOEP was successfully demonstrated with nanospheres to increase sensor performance.
authors.affiliation: Multiscale Robotics Laboratory, Institute of Robotics and Intelligent Systems, ETH Zurich, 8092, Switzerland. vidalp@ethz.ch
authors.forename: Olgac
authors.initials: O
authors.lastname: Ergeneman
authors.forename: George
authors.initials: G
authors.lastname: Chatzipirpiridis
authors.forename: Femke B
authors.initials: FB
authors.lastname: Gelderblom
authors.forename: Juho
authors.initials: J
authors.lastname: Pokki
authors.forename: Salvador
authors.initials: S
authors.lastname: Pané
authors.forename: Marta
authors.initials: M
authors.lastname: Marín Suárez Del Toro
authors.forename: Jorge F
authors.initials: JF
authors.lastname: Fernández Sánchez
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Sotiriou
authors.forename: B J
authors.initials: BJ
authors.lastname: Nelson
mesh_terms: D000465:Algorithms; D006801:Humans; D049449:Luminescence; D008280:Magnetics; D008299:Maleic Anhydrides / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008904:Miniaturization; D054118:Nanospheres; D036103:Nanotechnology / Q000379:methods; D009799:Ocular Physiological Phenomena; D055095:Optics and Photonics; D010100:Oxygen / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D012371:Robotics; D013997:Time Factors
chemical_list: D008299:Maleic Anhydrides; D011137:Polystyrenes; D010100:Oxygen