scholarly journals Pneumatically Actuated Thin Glass Microlens for On-Chip Multi-Magnification Observations

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 73
Author(s):  
Yusufu Aishan ◽  
Yaxiaer Yalikun ◽  
Yo Tanaka

This paper presents a self-contained micro-optical system that is magnification-controlled by adjusting the positions of the microlens in the device via pneumatic air pressure. Unlike conventional dynamic microlenses made from a liquid or polydimethylsiloxane (PDMS) that change their shapes via external actuation, this system combines a fixed-curvature glass microlens, an inflatable PDMS layer, and the external pneumatic air pressure supply as an actuator. This device showed several advantages, including stable inflation, firm structure, and light weight; it achieved a larger displacement using the glass microlens structure than has been reported before. This fixed-curvature microlens was made from 120 µm-thick flat thin glass slides, and the system magnification was manipulated by the deflection of a 100 µm-thick PDMS layer to alter the distance from the microlens to the microfluidic channel. The system magnification power was proportional to the air pressure applied to the device, and with a 2.5 mbar air pressure supply, a 2.2X magnification was achieved. This optical system is ideal for combining with high resolving power microscopy for various short working distance observation tasks, and it is especially beneficial for various chip-based analyses.

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.


Author(s):  
Jing Ren ◽  
Sriram Sundararajan

Realistic random roughness of channel surfaces is known to affect the fluid flow behavior in microscale fluidic devices. This has relevance particularly for applications involving non-Newtonian fluids, such as biomedical lab-on-chip devices. In this study, a surface texturing process was developed and integrated into microfluidic channel fabrication. The process combines colloidal masking and Reactive Ion Etching (RIE) for generating random surfaces with desired roughness parameters on the micro/nanoscale. The surface texturing process was shown to be able to tailor the random surface roughness on quartz. A Large range of particle coverage (around 6% to 67%) was achieved using dip coating and drop casting methods using a polystyrene colloidal solution. A relation between the amplitude roughness, autocorrelation length, etch depth and particle coverage of the processed surface was built. Experimental results agreed reasonably well with model predictions. The processed substrate was further incorporated into microchannel fabrication. Final device with designed wall roughness was tested and proved a satisfying sealing performance.


2007 ◽  
Vol 121-123 ◽  
pp. 611-614
Author(s):  
Che Hsin Lin ◽  
Jen Taie Shiea ◽  
Yen Lieng Lin

This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.


2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Ummikalsom Abidin ◽  
Jumril Yunas ◽  
Burhanuddin Yeop Majlis

Joule heating effect is substantial in an electromagnet system due to high density current from current-carrying conductor for high magnetic field generation. In Lab-on-chip (LoC) Magnetically Activated Cell Sorting (MACS) device, Joule heating effect generating high temperature and affecting the biological cells viability is investigated. The temperature rise of the integrated system was measured using resistance temperature detector, RTD Pt100. Three temperature rise conditions which are from the bare spiral-shaped magnet wire, the combination of magnet wire and on-chip magnetic core and combination of magnet wire, on-chip magnetic core and 150 mm polydimethylsiloxane (PDMS) layer have been investigated.  The combination of electromagnet of spiral-shaped magnet wire coil and on-chip magnetic core has reduced the temperature significantly which are, ~ 38 %  and ~ 26 % with magnet wire winding, N = 10 (IDC = 3.0 A, t = 210 s) and N = 20 (IDC = 2.5 A, t = 210 s) respectively. The reduced Joule heating effect is expected due to silicon chip of high thermal conductivity material enable fast heat dissipation to the surrounding.  Therefore, the integration of electromagnet system and on-chip magnetic core has the potential to be used as part of LoC MACS system provided the optimum operating conditions are determined


2005 ◽  
Author(s):  
Prashanta Dutta ◽  
Keisuke Horiuchi ◽  
Huanchun Cui ◽  
Cornelius F. Ivory

This experimental study reports a method to increase the resolving power of isoelectric focusing (IEF) on a polymeric microfluidic chip. Microfluidic chip is formed on poly-di-methyl siloxane (PDMS) using soft lithography and multilayer bonding technique. In this novel bioseparation technique, IEF is staged by first focusing protein species in a straight channel using broad-range ampholytes and then refocusing segments of that first channel into secondary channels that branch out from the first one. Experiments demonstrated that three fluorescent protein species within a segment of pH gradient in the first stage were refocused in the second stage with much higher resolution in a shallower pH gradient. A serially performed two-stage IEF was completed in less than 25 minutes under particularly small electric field strength up to 100 V/cm.


Author(s):  
Shahab O. Dabironezare ◽  
Kenichi Karatsu ◽  
Stephen J. C. Yates ◽  
Alejandro Pascual Laguna ◽  
Vignesh Murugesan ◽  
...  
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2019 ◽  
Vol 10 (1) ◽  
pp. 179 ◽  
Author(s):  
Hojong Choi ◽  
Jaemyung Ryu

Conventionally, a bright, very wide-angle optical system is designed as a floating type optical system that moves two or more lens groups composed of multiple lens in order to focus accurately. These have been widely used as phase detection auto focus (AF) methods within conventional digital single-lens reflex (DSLR) cameras. However, a phase detection AF optical system cannot be used when recording motion pictures. In contrast, a compact system camera (CSC) performs AF by the contrast method, where a stepper motor is used as the driving source for moving the optical lens. Nonetheless, to ensure that the focusing lens is lighter, these stepper motors should not have high torque and AF must be possible by moving only one lens. Yet, when focusing is performed with only one lens, aberration change due to focusing lens movement is magnified. Therefore, a very wide-angle optical system comprised of a half-angle of view more than 40 degrees and F of 1/4 has not been developed. Here, a very wide-angle optical system was designed with high resolving power that enables high speed AF, even in contrast mode, by moving only one lens while minimizing aberration change.


2013 ◽  
Vol 177 ◽  
pp. 472-477 ◽  
Author(s):  
Kwi Nam Han ◽  
Cheng Ai Li ◽  
Minh-Phuong Ngoc Bui ◽  
Xuan-Hung Pham ◽  
Bum Sung Kim ◽  
...  

2004 ◽  
Vol 76 (21) ◽  
pp. 6426-6433 ◽  
Author(s):  
Haiyun Qu ◽  
Haitao Wang ◽  
Yi Huang ◽  
Wei Zhong ◽  
Haojie Lu ◽  
...  

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