Figure legends
Figure 1. (a) Vertical electrodes to measure the capacitance of
cells in a hydrogel with vertical resolution. (b) Real-time capacitance
of hydrogels seeded with different cell concentrations. (c) Fluorescent
optical images of hydrogels containing different cell densities. (scale
bar: 100 μm). Reproduced with permission.(S.-M. Lee et al., 2016)
Copyright 2015, Elsevier B.V.
Figure 2. (a) Horizontal electrodes for measuring cells in
hydrogel using the hanging-drop technique. (b) Correlation between cell
number and impedance magnitude measured at discrete frequencies (500,
1000 and 5000 Hz). Reproduced with permission.(Lei et al., 2018)
Copyright 2017, Elsevier B.V.
Figure 3. (a) Schematic of the parallel electrodes for the
impedance biosensor. (b) Equivalent circuit of cells in 3D within the
matrigel. (c) Measurement of cells in 3D culture using the parallel
electrodes (3D ECMIS). Reproduced with permission.(Pan et al., 2019)
Copyright 2018, Elsevier B.V.
Figure 4. (a) Schematic of the poly(3,4-ethylenedioxythiophene)
xanthan gum (PEDOT:xanthan) electroactive scaffold used to host and
monitor cells. (b) Impedance spectrum of the scaffold with no cells
(blue), after cell growth within the scaffold over 7 days (red) and
PEDOT:xanthan gum scaffold after 7 days of incubation (37 °C, 5% CO2)
in culture media without cells (dashed lines). Reproduced with
permission.(Del Agua et al., 2018) Copyright 2018, American Chemical
Society. (c) Typical impedance spectrum of 2D cells grown on electrodes.
Reproduced with permission.(Del Agua et al., 2018) Copyright 2015,
Elsevier B.V.
Figure 5. Equivalent circuit and typical impedance spectrum of
cells in 2D. Adapted with permission.(Benson et al., 2013) Copyright
2013, BioMed Central Ltd.
Figure 6. Parallel impedance electrodes to measure the maturity
of a reconstructed human epidermis (RHE). (a) Detailed view of one
measurement chamber with a RHE in a transwell insert and equivalent
circuit. (b) Bode plots of impedance spectra from RHE at different time
points. Reproduced with permission.(Groeber et al., 2015) Copyright
Groeber et al., 2014.
Figure 7. (a) Radially distributed circular electrodes (adapted
from (Yin et al., 2018)) (b) Rectangular electrodes at the boundary of
the well were used to monitor spheroid and (c) reconstructed images for
the spheroid samples in 2% Triton X-100 solution (1-2) and HG culture
medium (3-4). Reproduced with permission.(Wu, Yang, et al., 2018; Wu,
Zhou, et al., 2018) Copyright Wu et al., 2018.
Figure 8. The electrode design shows the placement of current
injecting electrodes on parallel walls and the placement of voltage
sensing electrodes on the bottom surface as well as the two parallel
walls. Reproduced with permission.(E. J. Lee et al., 2014) Copyright Lee
et al.; licensee BioMed Central Ltd. 2014.