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Publications

by Keyword: Electric excitation

Robbiani, Stefano, Benegiamo, Alessandro, Capelli, Laura, Marco, Santiago, Dellaca, Raffaele, (2024). Dielectric excitation of Metal Oxide Semiconductor sensors: an exploratory performances analysis 2024 Ieee International Symposium On Olfaction And Electronic Nose (Isoen)

Metal Oxide Semiconductor (MOX) sensors are among the most widespread devices in chemical sensing, but their use is hindered due to several limitations, including crosssensitivity to temperature and humidity. Few studies suggested that the dielectric excitation readout of MOX sensors can increase the linearity and reduce cross-sensitivity. A bench test on two commercially available MOX sensors was designed and used to evaluate the dielectric excitation readout performances at different concentrations of acetone and ethanol when temperature and humidity were changed. Results show that not only both the real and imaginary parts of the sensors' electrical impedance are strongly frequency dependent, but also the dynamics of the sensors' response. Furthermore, the calculation of cross-sensitivity shows that there are regions of the spectra that allow for a reduction of cross-sensitivity to environmental interferences ranging from 2 to 10 times between 50 and 100 KHz.

JTD Keywords: Confounding factor, Dielectric excitation, Metal oxide semiconductor sensors


Dias, JMS, Estima, D, Punte, H, Klingner, A, Marques, L, Magdanz, V, Khalil, ISM, (2022). Modeling and Characterization of the Passive Bending Stiffness of Nanoparticle-Coated Sperm Cells using Magnetic Excitation Advanced Theory And Simulations 5, 2100438

Of all the various locomotion strategies in low- (Formula presented.), traveling-wave propulsion methods with an elastic tail are preferred because they can be developed using simple designs and fabrication procedures. The only intrinsic property of the elastic tail that governs the form and rate of wave propagation along its length is the bending stiffness. Such traveling wave motion is performed by spermatozoa, which possess a tail that is characterized by intrinsic variable stiffness along its length. In this paper, the passive bending stiffness of the magnetic nanoparticle-coated flagella of bull sperm cells is measured using a contactless electromagnetic-based excitation method. Numerical elasto-hydrodynamic models are first developed to predict the magnetic excitation and relaxation of nanoparticle-coated nonuniform flagella. Then solutions are provided for various groups of nonuniform flagella with disparate nanoparticle coatings that relate their bending stiffness to their decay rate after the magnetic field is removed and the flagellum restores its original configuration. The numerical models are verified experimentally, and capture the effect of the nanoparticle coating on the bending stiffness. It is also shown that electrostatic self-assembly enables arbitrarily magnetizable cellular segments with variable stiffness along the flagellum. The bending stiffness is found to depend on the number and location of the magnetized cellular segments. © 2022 The Authors. Advanced Theory and Simulations published by Wiley-VCH GmbH.

JTD Keywords: cilia, flagella, flagellar propulsion, low reynolds numbers, magnetic, microswimmers, passive, sperm cell, Bending stiffness, Cells, Cellulars, Coatings, Decay (organic), Electric excitation, Excited states, Flagellar propulsion, Locomotion strategies, Low reynolds numbers, Magnetic, Magnetic excitations, Nanoparticle coatings, Passive, Propulsion methods, Self assembly, Simple++, Sperm cell, Sperm cells, Stiffness, Travelling waves, Variable stiffness, Wave propagation, Younǵs modulus