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UID:event-69@tuemeche.nl
DTSTAMP:20261007T234737Z
DTSTART;TZID=Europe/Amsterdam:20261109T133000
DTEND;TZID=Europe/Amsterdam:20261109T150000
SUMMARY:Actuation & Sensing Modules for Standardized Organ-on-Chip Platfo
 rms
DESCRIPTION:Speaker: Jia-Jun Yeh\nHost: Jaap den Toonder\n\nOrgan-on-chip
  (OoC) platforms are advanced cell culture systems that can emulate human
  tissues and diseases for mechanistic studies\, potentially conducive to 
 improved drug development and personalized therapy guidance. These platfo
 rms provide a representative tissue microenvironment including microfluid
 ic perfusion and controlled mechanical stimulation to synthetically repli
 cate in vivo-like conditions that static in vitro models cannot provide. 
 This is particularly relevant for barrier tissues\, where function is tie
 d directly to flow\, transport dynamics\, and integrity of cell layers. T
 ranslating OoC technology into routine laboratory practice requires platf
 orms that are not only biologically relevant but also modular in design\,
  compatible with standardized formats\, and capable of continuous functio
 nal readout. This thesis contributes to realizing such a platform through
  the development of three technical modules with integrated functionaliti
 es tailored for perfusion and electrical barrier sensing\, each designed 
 for biological\, mechanical and electrical compatibility with an ISO-comp
 atible OoC platform.\nThe first module introduces magnetic artificial cil
 ia (MAC) as a tubeless on-chip micropumping mechanism. Flexible magnetic 
 elastomeric cilia integrated in a microfluidic chip perform tilted conica
 l motion when driven by an external rotating permanent magnet\, and this 
 motion generates net fluid displacement at low Reynolds number. Prior wor
 k has demonstrated MAC-driven fluid pumping in closed microfluidic loops.
  Here\, the mechanism is adopted within a MAC module and characterized wi
 thin a standardized OoC platform\, achieving flow rates of up to 40 uL/mi
 n across a range of hydraulic loads\, tunable through actuation frequency
 . A key result is the continuous circulation of human monocytes at actuat
 ion frequencies up to 100 Hz. Cell viability and cytokine secretion profi
 les remain statistically comparable to static controls\, proving that the
  gentle nature of MAC actuation is compatible with circulating mechanical
 ly sensitive cells in suspension.\nThe second module targets transepithel
 ial electrical resistance (TEER) measurement\, the standard label-free me
 tric for tight-junction integrity in epithelial and endothelial barriers.
  A silicon-microfabricated sensor chip with titanium nitride electrodes p
 atterned on slanted sidewalls\, combined with a silicon nitride microporo
 us membrane\, implements four-electrode impedance spectroscopy with a geo
 metry designed to achieve uniform current distribution across the cell la
 yer. Reusable packaging with magnetic clamping and leak-free microfluidic
  interconnects allows repeated disassembly and assembly of the module wit
 hout loss of measurement integrity. Electrode functionality and stability
  is confirmed over multi-day culture periods\, providing the performance 
 baseline needed for the module to serve as reliable sensor in standardize
 d barrier assays.\nThe third module uses organic electrochemical transist
 ors (OECTs) for continuous barrier monitoring under perfusion. OECTs ampl
 ify the ionic signal from the cell layer through volumetric electrochemic
 al doping of the transistor channel\, offering a sensitivity advantage ov
 er passive impedance measurements at physiologically relevant signal leve
 ls. Photo-patterned PEDOT:PSS and p(g2T-TT) channels are evaluated\, and 
 gate configurations are systematically compared. A separated Ag/AgCl gate
  compartment coupled through a poly(vinyl alcohol)/KCl salt bridge is ide
 ntified as the most suitable configuration\, decoupling gate polarization
  and decreasing silver leaching into the cell culture medium. Integrated 
 on the standardized platform\, the OECT module can track Caco-2 tight-jun
 ction formation continuously and it can resolve pharmacological disruptio
 n of the barrier in real time.\nThe work presented in this thesis demonst
 rates that actuation and sensing functions can be realized as modular\, i
 ndependently characterized units within a single ISO-compatible platform.
  Together\, the three modules provide controlled tubeless perfusion and c
 ell circulation\, continuous impedance-based barrier monitoring\, and tra
 nsistor-based sensing with stable performance under fluid flow. More broa
 dly\, this thesis shows how these functions can be combined within a shar
 ed standardized framework\, providing a foundation for reproducible and s
 calable OoC workflows in circulating cells and barrier tissue research.
LOCATION:Atlas 0.710
URL:https://tuemeche.nl/peoplepages/event.php?id=69
CATEGORIES:PhD Defense
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