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We present a super wide-measurement range load sensor with high-durability for multi-biosignal sensing in daily life. We employed quartz crystal resonator (QCR) load sensor with super wide range (from 6 × 10−5 to 30 [N]) for sensing of biosignals ranging from mN order (e.g. heartbeat) to 100 N order (e.g. body motion). Furthermore, we implemented an outer case which makes the sensor durable against...
This paper proposes the method for mechanical characterization of floating cells on a microfluidic chip. We measured the reactive force of cells on the chip by applying mechanical deformation to the cells. Particularly we focused on the method to improve the sensing resolution of the probe position by using the phase detection of moiré fringe. This method realized approximately ten times higher resolution...
High-sensitive, wide-measurement range, and small-sized load sensor was developed using AT-cut quartz crystal resonator (QCR). The quartz crystal generates a charge, which is proportional to the external force. Since it has high sensitivity and excellent temperature stability, it has been used for various sensors. In particular, QCR has superior characteristic for static load sensing in nature. However,...
During the deformability test of Red Blood Cell (RBC) by utilizing a micro fluidic channel, we found an interesting phenomenon where some RBCs behave just like elastic pinball with the motion in the perpendicular direction with respect to the main flow line, while most of RBCs simply move along the main flow line. This phenomenon is called “Cell Pinball”. Through visualization, we found that the RBC...
We successfully established a wafer level fabrication process of the quartz crystal resonator (QCR) load sensor using atomic diffusion bonding. The proposed sensor has three-layer structures; two Si-hold layers and a quartz layer. Using microfabrication and atomic diffusion bonding, the assembly process was simplified. The fabrication process enables further miniaturization of the QCR sensor due to...
We present a novel cell manipulation method using vibration-induced local flow in open chip environment. By applying circular vibration to micropillars on a chip, local whirling flow is induced around the micropillars. From the observation of this unique phenomenon, we propose the concept of cell manipulation in open chip environment. We analyze this phenomenon theoretically, and evaluate the effect...
This paper reports the on-chip Fluid Separated Volumetric Flow Converter (FSVFC) capable of high speed cell position control with high resolution. There are various situations where we need to avoid mixing working fluid and actuation fluid for biological considerations, and such demand motivates the development of FSVFC. The proposed on-chip comb shaped FSVFC is composed of two separated groups of...
BackgroundThere are several complications associated with Stent‐assisted Coil Embolization (SACE) in cerebral aneurysm treatments, due to damaging operations by surgeons and undesirable mechanical properties of stents. Therefore, it is necessary to develop an in vitro simulator that provides both training and research for evaluating the mechanical properties of stents.
MethodsA new in vitro simulator...
In order to achieve detection of flowing cells in the glass capillary, we proposed the integrated micropipette. In this research, we focused on the fabrication of microcapillary. The fabrication method is based on MEMS packaging technique. Two glass layer; a micro channel and a sensor layer are bonded, and we can get microcapillary with capacitance sensor for detection of cell flowing. By using fabricated...
We succeeded in isolating pre-counted small amounts of circulating tumor cells from whole blood. And we also confirmed isolation of CTCs from mouse-CTC model with same method. On our open microfluidic chip, CTCs are isolated by their size-difference from other blood cells. Therefore, we arranged micropillars on the microfluidic chip. Blood sample is injected between chip and inclined coverglass. And...
We have proposed a novel approach for applying mechanical stimulation to freely swimming microorganism inside of the microfluidic chip. Our approach is mainly based on continuously tracking the swimming microorganism under the microscope using a high-speed online vision sensor, and then applying the mechanical stimulation using high-speed on-chip microactuator. To realize our approach, we have developed...
In this paper, we present a novel method to investigate the mechanism driving nuclear translocation in migrating neurons via digital image analyses of the nucleus. We obtained and quantitatively analyzed time-lapse images of the fluorescently labeled nucleus with a high-speed confocal microscope. We focused on spatiotemporal dynamics of the boundary curvature of the nucleus during nuclear translocation...
This paper reports fabrication of retinal microvessel model for evaluation of microcannulation. Because microcannulation as a new treatment for retinal vein occlusion is difficult surgery operation, development and evaluation of microsurgical robot systems to assistant surgery is needed. Evaluation of microcannulation needs a retinal microvessels model. Therefore, we fabricated microvessel models...
In this paper we propose the method for the measurement of cellular mechanical response on a microfluidic chip. In order to improve the sensing resolution, we applied the principle of moiré fringe. As a result, the resolution of the measurement is approximately ten times higher than our previous research.
We present a super wide-measurement range load sensor with high-durability for multi-biosignal sensing in daily life. We employ quartz crystal resonator (QCR) load sensor with super wide range (from 6 × 10−5 to 30 [N]) for sensing of biosignal ranges from mN order (e.g. heartbeat) to 100 N order (e.g. body motion). Furthermore, we implement an outer case to make the sensor durable against unexpected...
We fabricated a microfluidic chip to detect purified influenza virus RNA using Quartz Crystal Microbalance (QCM). The channel made of PDMS (poly dimethylsiloxane) was combined with QCM directly. The targeted virus genome introduced to the channel was captured by Peptide Nucleic Acid (PNA) immobilized on the electrode of QCM. After this, we introduced the gold colloid to be captured by influenza virus...
We propose a novel concept for measuring the mechanical properties of a single cyanobacteria using a robot integrated microfluidic chip (robochip). We utilize direct-outer-drive mechanism for actuation of on-chip probe and optical tweezes for transportation of a single cell. We show the measurement results using Synechocystis sp. strain PCC 6803 which is a kind of cyanobacteria.
We newly discovered the zigzag motion of red blood cell(RBC) in microchannel where the height is slightly less than that of RBC. Through the visualization by attaching micro beads on the surface of RBC, we found that the cell continuously rotates during the zigzag motion and the clockwise rotating motion appears when RBC moves toward the right hand direction with respect to the flow line.
Evaluation of oocyte and embryo has become important for many biomedicai applications. We developed measurement of oxygen consumption rate of individual oocyte using fluorescence oxygen sensor having stripe-shape on a microfluidic chip. The fluorescence sensor was made of the mixture of polyethylene glycol diacrylate and Tris (2,2'-bipyridyl) dichloro ruthenium (II) hexahydrate (Ru(bpy)3Cl2). The...
A method for evaluating red blood cell (RBC) deformability by different channel width in a microfluidic device is proposed. While conventional methods usually have only one test channel to deform RBCs for the evaluation, a design including three test channels with different width is utilized in this work. The proposed design have the advantage of generating a wider range of deformation to each RBC,...
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