Advances in Polymer Technology

Review Article

Latest Updates on the Advancement of Polymer-Based Biomicroelectromechanical Systems for Animal Cell Studies

Table 1

Recent BioMEMS platforms for particle/cell sorting including the type of the platform, the main components, the fabrication strategy, the mechanism of operation, and the specifics of each platform.


BioMEMS platform	Main components	Fabrication strategy	Mechanism of operation	Specifics	Ref.

Microfluidic-based Raman ACS	Laser beam laser tweezer Raman microscopy PDMS-based microfluidic device	Standard soft lithography technique	Raman effect takes place when light illuminates a certain region of the microdevice. The photon interaction perturbs the electron configuration of the molecule to an unstable virtual state during the photon scattering, yielding the differences between particles.	The laser tweezers enable trapping of individual cells at the focus of the laser beam.	[15]
Micro/nanomotors for cancer cell targeting	Synthesized PS Janus particles	Wet etching and photolithography	The micromotors were designed to harness local H₂O₂ produced by cancer cells to convert chemical energy into mechanical propulsion while targeting specific cancer cells.	The design needs to overcome the low Reynolds number and Brownian motion, which work together against the motor’s locomotion.	[14]
Centrifugal microfluidic Chip	Charge-based microchannel flow	Standard soft lithography	By applying a voltage to the cells, monodisperse droplets were generated and manipulated.	The device encapsulates and sorts cells in one single step.	[10]
Single-molecule tracing microfluidic chip	Microchannels Acoustic wave transducer	Standard soft lithography	Acoustic waves push specific particles into cavities depending on their size and deformability.	The device can be used for organic and inorganic particle separation.	[11]
3D carbon-DEP microfluidic chip	3D-carbon electrodes voltage signal generator	Two-step photolithography process	DEP was used to separate death from live monocytes using 3D carbon electrodes. A voltage was applied to create an electric field. Live monocyte cells reacted to the attraction force and were trapped in the electric fields near the electrodes while dead cells remain unresponsive.	The strategy offers a contact-free procedure leading to more accurate analytical results.	[17]
DEP microfluidic chip	ITO electrodes Function generator Power supply Syringe pump Microfluidic device	Standard soft lithography	Following the channels, the cells were carried to the tumor-trapping zone, where tumor cells could not continue traveling through the device outlet due to their size and deformability.	The device is capable to induce cell sorting based on DEP by encapsulating particles in droplets and applying a voltage potential in a single step.	[18]
Microfluidic-based Raman ACS optofluidic platform	Raman microspectroscopy Laser beams Laser tweezers PDMS-based microfluidic device	Standard soft lithography	Cells from a sample fluid were flown into a microfluidic device and focused in the vertical and horizontal directions by two sheath flows. Cells captured by the optical tweezers were moved to the sample-free stream for spectrum measurement. Cells of interest were released into the collection outlet for further cultivation.	The device is capable of sorting four model bacteria while demonstrated a sorting accuracy of 98%, high-throughput performance by sorting up to 500 cells per hour, and compatibility with cultivation after collection of the cells.	[16]
DEP microfluidic chip	Au/Ti electrodes Function generator Power supply Syringe pump PDMS-based microfluidic device	Standard soft lithography, physical vapor deposition, and D.C. sputtering	A sample was injected in the microfluidic chip at a constant rate, following through the channels; the cells of interest were subjected to DEP forces and trapped in different areas.	The device is capable of separating three kinds of circulating cells. The proposed model for DEP-based cell stretching enables the integration of more reliable geometries that can potentially optimize the use of DEP for cell sorting.	[20]
DEP microfluidic chip with conductive PDMS	Ag-PDMS-based electrodes Power supply PDMS microfluidic chip	Standard soft lithography and multilayer lithography	Sorting was achieved by DEP forces while a solution of cells passed through the microfluidic device.	The device utilizes Ag-PDMS electrodes in a simple fabrication process. DEP is utilized at low DC voltages of less than 15 Vpp with a high frequency.	[19]

ACS: activated cell sorting; Ag-PDMS: silver-polydimethylsiloxane; CTCs: circulating tumor cells; DEP: dielectrophoresis; H₂O_2: hydrogen peroxide; ITO: indium tin oxide; LOC: Lab-on-a-Chip; PDMS: polydimethyl siloxane; PS: polystyrene; RACS: Raman activated cell sorting; Vpp: peak to peak voltage (Vpp); 3D: three dimensional.