On-chip actuation transmitter for enhancing the dynamic response of cell manipulation using a macro-scale pump

Abstract

An on-chip actuation transmitter for achieving fast and accurate cell manipulation is proposed. Instead of manipulating cell position by a directly connected macro-scale pump, polydimethylsiloxane deformation is used as a medium to transmit the actuation generated from the pump to control the cell position. This actuation transmitter has three main advantages. First, the dynamic response of cell manipulation is faster than the conventional method with direct flow control based on both the theoretical modeling and experimental results. The cell can be manipulated in a simple harmonic motion up to 130 Hz by the proposed actuation transmitter as opposed to 90 Hz by direct flow control. Second, there is no need to fill the syringe pump with the sample solution because the actuation transmitter physically separates the fluids between the pump and the cell flow, and consequently, only a very small quantity of the sample is required (<1 ll). In addition, such fluid separation makes it easy to keep the experiment platform sterilized because there is no direct fluid exchange between the sample and fluid inside the pump. Third, the fabrication process is simple because of the single-layer design, making it convenient to implement the actuation transmitter in different microfluidic applications. The proposed actuation transmitter is implemented in a lab-on-a-chip system for red blood cell (RBC) evaluation, where the extensibility of red blood cells is evaluated by manipulating the cells through a constriction channel at a constant velocity. The application shows a successful example of implementing the proposed transmitter. V C 2015 AIP Publishing LLC.

Transfer Function of Macro-Micro Manipulation on a PDMS Microfluidic Chip

“…Different frequencies of sinusoidal inputs are applied to the PZT actuator as the inputs of the transfer function, while the motions of micro-objects are tracked as the outputs. The maximum frequency of the input signal is up to 300 Hz SHM, which is more than double that of previous works [ 2 , 7 ]. The gains and phase at different frequencies are determined using a fast Fourier transform (FFT).…”

“…There are various situations where cell manipulation is required in microfluidic applications [ 1 ]. The manipulation speed and resolution have been previously achieved up to 130 Hz and 240 nm as moving a micro object in a simple harmonic motion (SHM) on a microfluidic chip [ 2 ]. In order to further improve the manipulation speed and accuracy, as well as for a better understanding of the system, it is important to know the transfer function of the system.…”

“…One of the advantages is that macro actuator, such as the piezoelectric (PZT) actuator shown in Figure 1 , or a linear slider, are commercially available so that it is very convenient to implement them into a manipulation system [ 3 , 4 ]. Another advantage is that the macro actuator can be repeatedly used since it is separated from the microfluidic chip, while a micro actuator is usually fabricated on the chip, and it is difficult to be re-used [ 2 , 5 ].…”

Gravity-Based Precise Cell Manipulation System Enhanced by In-Phase Mechanism

“…For example, Sakuma et al developed an on-chip cell manipulation system which can manipulate cells with a resolution as accurate as 240 nm [ 3 ]. Monzawa et al further improved the manipulation speed up to 130 Hz as to move cells along a sinusoidal trajectory in a microfluidic channel [ 4 ]. Although these systems have been successfully applied for the evaluation of cell deformability by observing cell deformation during the manipulation, such as in the cell fatigue test [ 5 ], only position-based control is not sufficient for detailed evaluation due to a lack of the information of the applied force on the cells.…”

On-chip pressure sensor using single-layer concentric chambers

“…The deformation chamber is a wide chamber with a large surface area, which softens the structural stiffness of the chamber, and makes it easy to deform. 8,9 The chamber is connected to the point of interest by a probe channel as indicated in the top view. The other concentric chamber, the sensing chamber, is located inside the deformation chamber.…”