Is Dielectrophoretic Movement through Micro
Channel with Asymmetric Surface Electrodes
Fabricated by Photolithography Technique Effective
to Sort Flowing Cell?
Shigehiro Hashimoto, Member IEEE
dept. Mechanical Engineering
Kogakuin University
Tokyo, Japan
shashimoto@cc.kogakuin.ac.jp
Abstract— A flow channel with surface electrode has been
designed to detect dielectrophoretic movement of floating
myoblast. In the micro flow-channel, a pair of asymmetricsurface electrodes of titanium coating (thickness of 200 nm)
were fabricated by photolithography technique: the triangularelectrode with the tip angle of 0.35 rad, and the rectangularelectrode of the flat edge as the reference. The cyclic
alternating square wave of the electric current was applied
between the electrodes. The suspension of C2C12 (mouse
myoblast cell line) was injected into the channel, and theshifted movement of each flowing cell was measured at the
microscopic movie image. Experimental results of the pilot test
show that the absolute value of the amplitude of theacceleration by the electric field, which is perpendicular to theflow direction, increases with the radius of each cell. The
shifted movement of 70 µm is realized at the adjusted electricparameters: the frequency of 3 MHz, and the amplitude ofelectric current of ±7.5 mA.
Keywords—
biomedical
engineering,cellsorting,dielectrophoresis, surface electrode, C2C12, photolithography

I. INTRODUCTION
The movement of a biological cell suspended in a
medium is governed by several factors: movement of themedium, gravity [1], electric force, Van der Waals force, andaffinity of the surface. In a lot of studies, various methods
have been applied to control the movement of cells in vitro:
the flow [2], the shear field [3], the filter, the slit [4–6], themagnetic field [7], the gravitational field [8], the laser [9],and the electric field [10]. These methods might contribute toseveral applications of the manipulation of cells [11]:detection of targeted cells [12], sorting of cells [13],arrangement of cells to make a tissue, and measurement of
the character of cells [14].
Movement of a charged particle depends on the electricfield. The effect is applied to the electrophoresis device [15].
When a particle is subjected to a non-uniform electric field,
the force acts even on the non-charged particle, because thepolarization generates in the particle. The phenomenon iscalled dielectrophoresis [16]. The force of dielectrophoresis
depends on the several parameters: the electrical property ofthe particle, the shape and the size of the particle [17], theelectrical property of the medium, and the electric field (theamplitude and the frequency).
Electrophoresis is a phenomenon, in which a particle is
moved by the Coulomb force between the charge of theparticle and the electric field. Dielectrophoresis [18], on the

XXX-X-XXXX-XXXX-X/XX/$XX.00 ©20XX IEEE

Kiyoshi Yoshinaka
Health and Medical Research InstituteNational Institute of Advanced Industrial Science & Technology
Tsukuba, Japank.yoshinaka@aist.go.jp

other hand, is a phenomenon, in which a particle moves dueto the interaction between the electric field and the charge
induced in the neutral particle, when the particle is placed ina non-uniform electric field. With the aid of the
micromachining technique [19], many kinds of microsystems were designed. In some systems, dielectrophoresis
was applied to sort biological cells floating in the medium.
In the present study, a flow channel with asymmetricsurface electrodes has been designed using thephotolithography technique to sort cells by thedielectrophoretic movement. After optimizing the electricparameters, the shifted movement has been analyzed inrelation to the radius of each floating cell in vitro.
II. METHODS
A. Design of Surface ElectrodeTo incorporate electrodes with the designed figure in the
micro flow-channel, the titanium film coating was used forthe surface electrode. The thickness of coating is 200 nm on
the glass plate. After several trials for optimization, thedesign of the electrodes were decided as follows. One of thesurface electrodes has a triangle shape with the tip angle of
0.35 rad. The other reference electrode has a flat edge (Fig.
1). The shortest connecting line between electrodes isvertical to the flow direction: 0.1 mm distance.
B. Deposition of Titanium
The surface of the glass plate was hydrophilized by theoxygen plasma ashing by the reactive ion etching system,
before the deposition of titanium. Titanium was deposited on
the surface of the glass plate in the electron beam vapor
deposition apparatus (Fig. 2). After a lot of trials, theprotocol of fabrication of the surface electrodes incorporated
micro flow-channel was made as follows.
C. Photomask A for Triangle Tip of ElectrodeThe positive photoresist material of OFPR-800LB was
coated on the titanium with the spin coater. The photoresist
was baked at the hotplate at 338 K for one minute and at 368
K for three minutes, successively.
The pattern of the electrode with the flow channel was
drawn on the photomask with a laser drawing system. The
photoresist was developed with tetra-methyl-ammoniumhydroxide for two minutes, rinsed with the distilled water,and dried.

The titanium coated plate was etched with the plasma gas
using RIE-10NR. For etching, the gas of SF6 with Ar wasapplied at 75 W at 4 Pa for seven minutes.

αyvy

D. Photomask B for ElectrodeThe titanium coated glass plate was hydrophilized by theoxygen plasma ashing by the reactive ion etching system.
The negative photoresist material of low viscosity (SU-8)
was coated on the titanium with the spin coater. The
photoresist was baked at the hotplate at 338 K for one minuteand at 368 K for three minutes, successively.
The photomask A was mounted on the surface of SU-8,
and the photoresist was exposed to the UV (ultraviolet) lightthrough the photomask in the mask aligner. The photoresist
was baked at the hotplate at 338 K for one minute and at 368
K for three minutes, successively. The photoresist wasdeveloped with SU-8 Developer. The glass surface with themicro pattern was rinsed with IPA (2-propanol) for one
minute, and with the pure water for one minute. After drying,
the plate was etched with the plasma gas using RIE-10NR.
For etching, the gas of SF6 with Ar was applied at 75 W at 4
Pa for seven minutes. The areas at the bands of both ends
were covered with the polyimide tapes (to protect thephotoresist material from the UV light) to leave the part oftitanium coating for extended electrodes.
E. Photolithography process for surface electrodes
The titanium coated glass plate was hydrophilized by theoxygen plasma ashing for five minutes at 100 W by thereactive ion etching system. The positive photoresist materialof OFPR-800LB was coated on the titanium with the spincoater. The photoresist was baked at the hotplate. The
photomask B was mounted on the surface of SU-8, and thephotoresist was exposed to the UV light through the mask inthe mask aligner. The photoresist was developed with tetramethyl-ammonium hydroxide (NMD-3) for two minutes,
rinsed with the distilled water. After drying, the plate wasetched with the plasma gas using RIE-10NR. For etching, thegas of SF6 with Ar was applied at 75 W at 4 Pa for sevenminutes.
F. Lower Plate of Flow Channel
To make the groove of the flow channel (width of 0.5mm, length of 18 mm, and depth of 0.04 mm), thephotomask C was made by the same process as thephotomask A. The surface of the electrodes washydrophilized by the oxygen plasma ashing by the reactive
ion etching system. The negative photoresist material of low
viscosity (SU-8) was coated on the surface electrodes withthe spin coater. The coating condition was adjusted to makethe layer of thickness (correspond to the height of the flow
channel) between 20 μm and 40 μm. The thickness of thelayer (SU-8) on the surface electrode was measured by thestylus (with 3×10−5 N) of the contact profilometer. The
photoresist was baked at the hotplate.
The photomask C was mounted on the surface of SU-8,
and the photoresist was exposed to the UV light through thephotomask in the mask aligner. The photoresist was baked at
the hotplate. The photoresist was developed with SU-8
Developer. The surface with the micro pattern was rinsed
with IPA, and with the pure water. The photoresist was
baked at the hotplate.

Electrode
αx

vx

y
O

Cell

x

Δy

Flow
Electric field

ElectrodeFig. 1. Two-dimensional movement of cell flowing near tip of electrode:
position (x, y), velocity (vx, vy), and acceleration (αx, αy) of cell.

Titanium

Photomask A

UV

SU-8 Coating
OFPR Coating

Developing
Drawing Laser

Etching
Developing
UV Photomask B UV

Etching

SU-8 Coating

Etching
Cleaning

Fig. 2. Photolithography process for surface electrodes.

G. Upper Plate of Flow Channel
Polydimethylsiloxane (PDMS) was poured into the moldof poly-methyl-methacrylate with the curing agent. The
volume ratio of PDMS to curing agent is ten to one. After
degassing, PDMS was baked at 353 K for two hours in theoven. The upper plate has holes with the diameter of 5 mm
for the inlet and the outlet of the suspension. The upper plate
was exposed to the oxygen gas in the reactive ion etchingsystem (FA-1), and coated with Aminopropyltriethoxysilane.
After ten minutes, the upper plate was adhered on the lower
plate under the pressure of 0.5 N/m2 by sandwiching between
plates of polymethylmethacrylate. The plates were baked in
the oven at 353 K for ten minutes. A rectangularparallelepiped channel of 18 mm length × 0.5 mm width ×
35 µm height is formed between upper and lower plates. The

flow channel is placed on the stage of the inverted phasecontrast microscope.
H. Electric Stimulation
The electric stimulation of the alternating square wave
(0.25 μs < period < 10 μs (0.1 MHz < frequency (f) < 4MHz); amplitude of ±5 V, ±10 V, or ±15 V) was generated
with an electric stimulator. The stimulator was connected tothe titanium film electrode, and the electric stimulation wasapplied to the medium flow. An electric resistance (R) of 2kΩ is serially inserted between the electrode and thestimulator. The electric signal between the terminals of theresistance (V) was monitored to measure the electric current
by an oscilloscope during the electric stimulation applied
between the titanium surface electrodes.
I. Cell
C2C12 (mouse myoblast cell line originated with crossstriated muscle of C3H mouse) was used in the test. D-MEM(Dulbecco’s Modified Eagle Medium) containing 10% FBS(Fetal Bovine Serum) and 1% penicillin/ streptomycin wasused for the medium.

III. RESULTS
The microscopic image (Fig. 3) exemplifies a cellflowing near the tip of the triangular electrode. The movie
showed the sifted movement of the flowing cell passing
adjacent to the tip of the electrode by dielectrophoresis.
Tracings of 20 cells under the electric stimulation is
exemplified in Fig. 4: the period of 0.3 μs, the amplitude of±15 V. Every cell shows the shifted movement perpendicular
to the flow direction near the tip (origin) of the triangularelectrode.
Fig. 5 shows the shifted distance (Δy) in relation to theamplitude of the rectangular alternating voltage (E) at thefrequency (f) of 3 MHz. The mark shows the mean value ofΔy, and the bar shows the standard deviation. The shifted
distance increases with the increase of the amplitude of thevoltage. With the amplitude of ±15 V, the electric current (I)was ±7.5 mA. To get enough shift movement, the amplitudeof ±15 V has been selected in Figs. 6-8.

Before the flow test, the inner surface of the flow channel
was hydrophilized by the oxygen plasma ashing. The bovine
serum albumin solution was prefilled in the flow channel,
and incubated for thirty minutes at 310 K in the incubator.

The relationship between the shifted distance (Δy) andthe frequency (f) of cyclic rectangular alternating electric
stimulation at the amplitude of ±15 V is displayed in Fig. 6.
The shifted distance increases with the frequency of thecyclic stimulation. To get enough shift movement, thefrequency higher than 3 MHz has been selected in Fig. 7 andFig. 8.

Before the flow test, cells were exfoliated from the plateof the culture dish with trypsin including EDTA
(ethylenediaminetetraacetic acid), and suspended in themedium. The suspension of cells was poured at the inlet ofthe flow channel. The flow was made by the pressure
difference between the inlet and the outlet, which was kept
by the gravitational level of the medium (< 5 mm).

Fig. 7 shows the tracings of the acceleration (αy) of 20
cells. The period of the rectangular cyclic wave is 0.25 μs.
Each cell is accelerated to the apart direction (−y direction
perpendicular to the flow) from the tip of the triangularelectrode before passing through the tip of the electrode, anddecelerated after passing through the tip of the electrode (+ydirection).

Each cell passing between the electrodes was observedby the inverted phase-contrast microscope, and recorded by
the video camera, which is set at the eyepiece of the
microscope. The contour of each cell was traced, and the
projected two-dimensional area (S) at the image of each cell
was calculated. The equivalent radius (r) was calculated by
(1).
S=πr2

Electrode

Cell

()

To trace the movement of the cell, the coordinates aredefined as that in Fig. 1. The main flow direction of themedium is defined as x. The direction perpendicular to x isdefined as y: the direction from the reference electrode to thetip of the triangular electrode. The origin is adjusted at the tipof the triangular electrode. Both the position (x0, y0) and thevelocity (v0) of each cell were measured at x = −0.4 mm(upstream from the tip of the electrode) as the initial value.
The shifted distance (Δy) was defined as the difference
between the maximum value of y coordinate and minimum
value of y coordinate according to the stream line of each cellin the range of x between −0.4 mm and 0.4 mm. The
components (vx, and vy) of velocity were calculated at theposition tracings of each cell. The components (αx, and αy) of
the acceleration of the velocity were calculated at thevelocity tracings of each cell. The maximum absolute valueof the acceleration (αymax) was defined according to thestream line of each cell in the range of x between −0.4 mm
and 0.4 mm (Fig. 8).

Flow

Electrode0.05 mmFig. 3. Cell (red circle) is passing adjacent to tip of electrode.

Fig. 8 displays the relationship among parameters by
three-dimensional graph: the maximum acceleration (αymax),
the radius (r), and the initial position (−90 µm < y0 < 60 µm).
The period of the rectangular cyclic wave is 0.3 μs. The
absolute value of the maximum amplitude of the acceleration(αymax) of the velocity of each cell during passing over the tipof the electrode is displayed in Fig. 8. The absolute value ofthe maximum amplitude of the acceleration (αymax) is high,when the cell flowing along the streamline “y0 = 0” throughthe tip of the electrode. The absolute value of the maximum
amplitude of the acceleration (αymax < 13 mm/s2) by theelectric field, which is perpendicular to the flow direction,
increases with the radius of the cell (r < 11 µm).
Fig. 4. Tracings of movement of 20 cells (μm): frequency of 3 MHz,amplitude of ±15 V.

2

Acceleration at perpendicular to flow, αy (mm/s )Shifted distance, Δy (µm)

Position at flow direction, x (µm)
Amplitude of voltage, E (V)2Fig. 7. Acceleration αy (mm/s ) tracings of 20 cells: frequency f of 4 MHz,amplitude E of ±15 V.

Fig. 5. Relationship between shifted distance Δy (µm) and amplitude ofvoltage E (V): mean (circle) ± standard deviation (bar), number of sample n= 4.

2

Acceleration αymax (mm/s )Shifted distance, Δy (µm)

O

Frequency, f (MHz)Radius, r (µm)

Initial position, y0 (µm)

2Fig. 6. Relationship between shifted distance Δy (µm) and frequency f(MHz) of electric stimulation: mean (mark) ± standard deviation (bar):
number of sample n = 4.

Fig. 8. Relationship among maximum acceleration αymax (mm/s ), radius r(µm), and initial position y0 (µm): frequency of 3 MHz, amplitude of ±15 V.

IV. DISCUSSION
To find optimum design of the microdevice for theexperiment of dielectrophoresis, variations were made atseveral parameters in previous studies: the shape ofelectrodes, and the waveform of the electric stimulation (theamplitude, and the frequency) [20]. At 4 MHz, thedielectrophoretic movement of each cell was not able to be
detected by alternating current of the sine wave. With thealternating current of the square wave at 4 MHz, on the other
hand, the dielectrophoretic movement of each cell has been
detected.
The rectangular fluctuating voltage between electrodes[21] with the amplitude of ±15 V (the amplitude of electric
current of ±7.5 mA) made the enlarged lateral shift of theflowing cell (Fig. 5). The amplitude of the electric
stimulation has been limited within the threshold value toprevent electrolysis [22] in the present study.
Dielectrophoresis was applied to the cell sorting system
as the minimally invasive method in a lot of previous studies[23]. Before passing through the non-uniform electric field in
the flow channel, both the initial position and the velocity[24] should be controlled.
In the present study, the dielectrophoretic movement of
the cell has been tried to be observed by the optical
microscope. In the present study, the couple of electrodes
arrangement with the shorter distance each other has notbeen designed, because the electrodes are not opticallytransparent to observe the movement near the electrodeoptically. The shift depends on the passing route position of
the cell relative to the position of the tip of the electrode. The
dielectrophoretic effect is highest adjacent to the tip of theelectrode [25].
Fig. 4 shows the two-dimensional movement of each cellin the x-y plane from the microscopic video image. The real
movement of each cell is three-dimensional. The movementof the perpendicular direction to x-y plane is very small,because the height (35 µm) of the flow channel is small
compared with the width (0.5 mm) of the flow channel in thepresent experiment. The height is also close to the diameter(d) of the cell (10 µm < d < 25 µm) used in the present study.
The position of the streamline of the target cell was tried tobe controlled before passing through the electric field area inthe previous study [26].
The movement of cells between surface electrodes
depends on the topography of surface electrodes (the angle ofthe tip) [27], which relates to non-uniformity of the electricfield. The higher slope of the electric field with nonuniformity is necessary to enlarge the movement of each cellaround the electrode.
In principle, dielectrophoretic effect increases with thediameter of the particle. In the present experiment, it isconfirmed that the acceleration of the cell along the electricfield (perpendicular to the flow direction) increases with theradius of the cell (Fig. 8). In the present microfluidic channel,
10 mm/s2 increase of the lateral acceleration has been
generated per 5 µm increase of the radius of the cell.
The shifted distance of each cell is rather small at thesingle pair of electrodes. If the lateral shift movement of thecell adjacent to the tip of the electrode is enlarged at thedownstream by the inertial movement, the method can beapplied to the cell sorting. In the present device, the lateralshift of 70 µm has been realized [28]. The lateral shift can beamplified by accumulation with the multi-electrodes systemon the flow channel [29]. The relationship between thestreamline of the cell and the position of the side wall of theflow channel should be considered for the continuous
movement of the cell downstream.
Polydimethylsiloxane is available to make the micro
surface topography [30] for experimental devices on
biological cells. Biological cells are sensitive to the micro
surface topography on the scaffold [31]. The micro grooves,on the other hand, were used for trapping of flowing cells in
the previous study [32]. The system had capability toseparate the malnourished cell.
In the previous studies, dielectrophoresis was tried to be
applied to the biological cell manipulation technology [33].
The present study shows that the dielectrophoretic movement
through the micro channel with asymmetric surface
electrodes fabricated by the photolithography technique iseffective to sort flowing cells. The cell sorting technology
would be applied to tissue engineering [34] (e.g., the bioactuator made from myoblasts [35]). The cell sorting can beapplied to select targeted cells to improve the efficiency tomake the tissue. The cell sorting technology would also be
applied to diagnostics in medicine: detection of cancer cells[36].
V. CONCLUSION
The flow channel with asymmetric electrodes has been
designed by photolithography technique to detect
dielectrophoresis. The micro system has realized that theabsolute value of the amplitude of the acceleration by theelectric field, which is perpendicular to the flow direction,
increases with the radius of the cell.
ACKNOWLEDGMENT
The authors thank to Mr. Daisuke Hasegawa and to Mr.
Ryota Matsuzawa for their assistance of the experiment.
REFERENCES
[1]

[2]

[3]

[4]

[5]

[6]

[7]

S. Hashimoto, “Oblique micro grooves on bottom wall of flow
channel to sort cells,” Proc. ASME 2020 Fluids Engineering
Division Summer Meeting, FEDSM2020-20096, 2020, pp. 1–6.
A. Tabll, and H. Ismail, “Chapter 7: The use of flow cytometricDNA ploidy analysis of liver biopsies in liver cirrhosis andhepatocellular carcinoma,” Liver Biopsy, H. Takahashi, Ed, Intech
Open Limted, 2011, pp. 88–107.
S. Hashimoto, H. Sugimoto, and H. Hino, “Effect of couette type ofshear stress field with axial shear slope on deformation andmigration of cell: comparison between C2C12 and HUVEC,”
Journal of Systemics, Cybernetics and Informatics, vol. 17, no. 2,
2019, pp. 4–10.
S. M. McFaul, B. K. Lin, and H. Ma, “Cell separation based on sizeand deformability using microfluidic funnel ratchets,” Lab on a
Chip, vol. 12, 2012, pp. 2369–2376.
Y. Takahashi, S. Hashimoto, H. Hino, and T. Azuma, “Design ofslit between micro cylindrical pillars for cell sorting,” Journal of
Systemics, Cybernetics and Informatics, vol. 14, no. 6, 2016, pp. 8–
14.
S. Hashimoto, “Micro machined slit between ridge and groove in
micro fluid-channel to measure floating cell deformablity,” Proc.
ASME 2020 Fluids Engineering Division Summer Meeting,
FEDSM2020-20073, 2020, pp. 1–7.
M. Heijazian, W. Li, and N. T. Nguyen, “Lab on a chip forcontinuous-flow magnetic cell separation,” Lab on a Chip, vol. 15,
no. 4, 2015, pp. 959–970.

H. Imasato, and T. Yamakawa, “Measurement of dielectrophoretic
force by employing controllable gravitational force,” Journal of
Electrophoresis, vol. 52, no. 1, 2008, pp. 1–8.
[9] A. Miyakawa, T. Ishikawa, and Y. Kawata, “The examination ofbasic condition of the single cell isolation with laser,” Laser
Original, vol. 39, no. 2, 2011, pp. 123–128.
[10] D. R. Gossett, W. M. Weaver, A. J. Mach, S. C. Hur, H. T. K. Tse,W. Lee, H. Amini, and D. DiCarlo, “Label-free cell separation andsorting in microfluidic systems,” Analytical and Bioanalytical
Chemistry, vol. 397, 2010, pp. 3249–3267.
[11] B. Yafouz, N. A. Kadri, and F. Ibrahim, “Dielectrophoretic
manipulation and separation of microparticles using microarray dot
electrodes,” Sensors, vol. 14, no. 4, 2014, pp. 6356–6369.
[12] P. R. C. Gascoyne, X. B. Wang, Y. Huang, and F. F. Becker,“Dielectrophoretic separation of cancer cells from blood,” IEEE
Transactions on Industry Applications, vol. 33, no. 3, 1997, pp.
670–678.
[13] M. D. Vahey, and J. Voldman, “An equilibrium method forcontinuous-flow cell sorting using dielectrophoresis,” Analytical
Chemistry, vol. 80, no. 9, 2008, pp. 3135–3143.
[14] T. Müller, A. Pfennig, P. Klein, G. Gradl, M. Jäger, and T. Schnelle,“The potential of dielectrophoresis for single-cell experiments,”
IEEE Engineering in Medicine and Biology Magazine, no. 11/12,
2003, pp. 51–61.
[15] X. Xuan, B. Xu, and D. Li, “Accelerated particle electrophoretic
motion and separation in converging-diverging microchannels,”
Analytical Chemistry, vol. 77, no. 14, 2005, pp. 4323–4328.
[16] H. Imasato, and T. Yamakawa, “Measurement of dielectrophoretic
force by employing controllable gravitational force,” Journal of
Electrophoresis, vol. 52, no. 1, 2008, pp. 1–8.
[17] Y. Kang, D-D. Li, S. A. Kalams, and J. E. Eid, “DCdielectrophoretic separation of biological cells by size,” Biomedical
Microdevices, vol. 10, no. 2, 2008, pp. 243–249.
[18] H. C. Shim, Y. K. Kwak, C. S. Han, and S. Kim, “Effect of a squarewave on an assembly of multi-walled carbon nanotubes using AC
dielectrophoresis,” Physica E, vol. 41, 2009, pp. 1137–1142.
[19] B. H. Jo, L. M. Van Lerberghe, K. M. Motsegood, and D. J. Beebe,“Three-Dimensional
Micro-Channel
Fabricationin
Polydimethylsiloxane(PDMS)
Elastomer,”
JournalofMicroelectromechanical Systems, vol. 9, no. 1, 2000, pp. 76–81.
[20] Y. Takahashi, S. Hashimoto, R. Yamauchi, H. Hino, and T. Yasuda,“Myoblast behavior around surface electrodes in flow channel,”Proc. 21st World Multi-Conference on Systemics Cybernetics andInformatics, vol. 2, 2017, pp. 251–256.
[21] H. Chu, I. Doh, and Y. H. Cho, “A three-dimensional (3D) particle
focusing channel using the positive dielectrophoresis (pDEP)
guided by a dielectric structure between two planar electrodes,” Labon a Chip, vol. 9, no. 5, 2009, pp. 686–691.
[22] G. Mernier, N. Piacentini, T. Braschler, N. Demierrea, and P.
Renaud, “Continuous-flow electrical lysis device with integrated
control by dielectrophoretic cell sorting,” Lab on a Chip, vol. 10, no.
16, 2010, pp. 2077–2082.
[23] K. Zhao, L. B. P. Duncker, and D. Li, “Continuous cellcharacterization and separation by microﬂuidic alternating current
dielectrophoresis,” Analytical Chemistry, vol. 91, 2019, pp. 6304–
6314.
[8]

[24] J. G. Gao, R. Riahi, M. L. Y. Sina, S. Zhang, and P. K. Wonga,“Electrokinetic focusing and separation of mammalian cells in
conductive biological fluids,” Analyst, vol. 137, no. 22, 2012, pp.
5215–5221.
[25] Y. Wakizaka, M. Hakoda, and N. Shiragami, “Effect of electrodegeometry on dielectrophoretic separation of cells,” Biochemical
Engineering Journal, vol. 20, no. 1, 2004, pp. 13–19.
[26] X. Chen, Y. Ren, W. Liu, X. Feng, Y. Jia, Y. Tao, and H. Jiang, “Asimplified microfluidic device for particle separation with twoconsecutive steps: induced charge electro-osmotic prefocusing anddielectrophoretic separation,” Analytical Chemistry, vol. 89, 2017,
pp. 9583−9592.
[27] N. Demierre, T. Braschler, P. Linderholm, U. Seger, H. van Lintel,
and P. Renaud, “Characterization and optimization of liquid
electrodes for lateral dielectrophoresis,” Lab on a Chip, vol. 7, no. 3,
2007, pp. 355–365.
[28] S. Hashimoto, R. Matsuzawa, and Y. Endo, “Analysis ofdielectrophoretic movement of floating myoblast near surface
electrodes in flow channel,” Proc. 11th International MultiConference on Complexity Informatics and Cybernetics, vol. 2,
2020, pp. 13−18.
[29] J. Giesler, G. R. Pesch, L. Weirauch, M. P. Schmidt, J. Thöming,and M. Baune, “Polarizability-dependent sorting of microparticles
using continuous-flow dielectrophoretic chromatography with afrequency modulation method,” Micromachines, vol. 11, no. 38,
2019, pp. 1–14.
[30] P. N. Carlsen, Ed., Polydimethylsiloxane: Structure andApplications, Nova Science Publishers, 2020 (S. Hashimoto,Application of polydimethylsiloxane: microstructure of functionalsurface for observation of biological cell behavior, pp. 29–94).
[31] S. Hashimoto, and K. Abe, “Monitoring of orientation of cells byelectric impedance: test on oriented cells using micro striped
grooves pattern by photolithography,” Proc. IEEE 19thInternational Conference on Bioinformatics and Bioengineering(BIBE), 2019, pp. 557–562.
[32] Y. Takahashi, S. Hashimoto, H. Hino, A. Mizoi, and N. Noguchi,“Micro groove for trapping of flowing cell,” Journal of Systemics
Cybernetics and Informatics, vol. 13, no. 3, 2015, pp. 1–8.
[33] H. Shafiee, J. L. Caldwell, M. B. Sano, and R. V. Davalos,“Contactless dielectrophoresis: a new technique for cellmanipulation,” Biomedical Microdevices, vol. 11, no. 5, 2009, pp.
997–1006.
[34] C. A. Powell, B. L. Smiley, J. Mills, and H. H. Vandenburgh,“Mechanical stimulation improves tissue-engineered humanskeletal muscle,” American Journal of Physiology - Cell
Physiology, vol. 283, no. 5, 2002, pp. C1557–C1565.
[35] S. V. Anand, M. Y. Ali, and M. T. A. Saif, “Cell culture on
microfabricated one-dimensional polymeric structures for bioactuator and bio-bot applications,” Lab on a Chip, vol. 15, no. 8,
2015, pp. 1879–1888.
[36] J. An, J. Lee, S. H. Lee, J. Park, and B. Kim, “Separation ofmalignant human breast cancer epithelial cells from healthyepithelial cells using an advanced dielectrophoresis-activated cell
sorter (DACS),” Analytical and Bioanalytical Chemistry, vol. 394,
no. 3, 2009, pp. 801–809.