- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2020 8th International Winter Conference on Brain-Computer Interface (BCI) - Gangwon, Korea (South) (2020.2.26-2020.2.28)] 2020 8th International Winter Conference on Brain-Computer Interface (BCI) - Implementation of multi-connected single-channel functional near-infrared spectroscopy system for hyperscanning study
摘要： A drug delivery system is used for targeting drugs to specific cells. Various drug carriers, that also reduce the side effects of unbound drugs, have been introduced and commercialized in the pharmaceutical field. Among them, synthetic biodegradable polymers have received much attention attributed to their low toxicity, controllable biodegradation rates, manufacturability, and low costs. This paper reviews the salient characteristics of biodegradable polymers as drug carriers and their microfabrication methods. The reviewed microfabrication methods include laser micromachining, rapid prototyping, replication, emulsification, microfluidic fabrication, and X-ray-lithography-based methods. For these microfabrication methods, critical dimensions, feature variety, solvent compatibility, production throughput, and tooling requirements are also summarized.
关键词： poly-capro-lactone (PCL),laser micromachining,emulsification,microfluidics,poly(lactic-co-glycolic acid) (PLGA),biodegradable polymers,Drug delivery systems (DDS),rapid prototyping,replication,x-ray-lithography,microfabrication,drug carriers
更新于2025-09-19 17:13:59
-
[IEEE 2019 International Conference on Electromechanical and Energy Systems (SIELMEN) - Craiova, Romania (2019.10.9-2019.10.11)] 2019 International Conference on Electromechanical and Energy Systems (SIELMEN) - Flexible Polynomial Mathematical Model of a Photovoltaic Power Plant
摘要： We report on a distributed circuit model for multi-color light-actuated optoelectrowetting devices. The model takes into consideration the large variation of absorption coefficient (15×) of photoconductors in the visible spectrum and the nonuniform distribution of photogenerated carriers. With the help of this model, we designed opto-electrowetting devices with optimum thickness of photoconductors. This leads to significant improvement in performance compared with prior reports, including 200× lower optical power, 5× lower voltage, and 20× faster droplet moving speed. This enables the use of commercial projectors to create on-demand “virtual” electrodes for large-scale parallel manipulation of droplets. We have achieved simultaneous manipulation of 96-droplet array. Finally, we have demonstrated parallel on chip detection of Herpes Simplex Virus Type 1 within 45 min using a real-time isothermal polymerase chain reaction assay.
关键词： light-actuated digital microfluidics,electrowetting,polymerase chain reaction (PCR),Droplet microfluidics,optoelectrowetting
更新于2025-09-16 10:30:52
-
Selective infiltration and storage of picoliter volumes of liquids into sealed SU-8 microwells
摘要： This paper describes the selective infiltration and storage of picoliter volumes of water and IPA in arrays of sealed SU-8 microwells. Microwells, with a volume of approximately 300 picoliters, are fabricated employing photolithography and a polymer onto polymer lamination method to seal the structures with a thin cover of SU-8 and PDMS in order to suppress the evaporation of the infiltrated liquids. A glass capillary is used to punch through the SU-8/PDMS cover and to infiltrate the liquid of interest into the microwells. The influence of the mixing ratio of the PDMS and its curing agent is studied and the results show that a lower ratio of 2:1 suppresses the evaporation more when compared to the standard mixing ratio of 10:1. In regards to water and IPA, the dwell time in the reservoirs was increased by approximately 50 % and 450 % respectively. Depending on the physical properties of the microwells and the liquids, the SU-8/PDMS cover suppresses the evaporation up to 32 mins for water and 463 mins for IPA, respectively, until the microwell is completely empty again. Additionally, multiple infiltrations of the same microwell are demonstrated using two immiscible liquids IPA and paraffin oil. Based on the popular polymers SU-8 and PDMS, the sealed microwell structures are scalable and combinable with different glass capillaries according to the needs of future analytical research and medical diagnostics.
关键词： microwells,Lab-on-a-chip,microfluidics,Selective infiltration,PDMS,SU-8
更新于2025-09-16 10:30:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - In Flow Manipulation and Characterization of Cancer Cells by Coherent Computational Microscopy
摘要： Liquid biopsy has shown remarkably promising in oncology for the early diagnosis of cancer through the detection of circulating biomarkers such as circulating tumor cells (CTCs). Recent evidences suggest that CTCs represent effective prognostic and predictive biomarkers to monitor/predict therapy efficacy in breast, colon and prostate cancers [1,2]. However, the frequency of CTCs in blood is approximately 1 to 10 cells per 10 mL of blood, which is as challenging as looking for a needle in a haystack. In microfluidics, Digital Holography (DH) has been shown to be a promising technique to characterize CTCs with the aim to detect them inside a heterogeneous liquid sample. DH is label-free, real-time and gives access to the complex amplitude of the object [3-6]. Thus, any classification approach based on the holographic signature can exploit a reach information content to take a decision. Moreover, the flexible refocusing capability of DH imaging allows to inspect an entire liquid volume with a single capture. This enables the high-throughput inspection of blood and other bodily fluids rapidly flowing inside microfluidic channels. In DH, the sample is probed from one single direction and the phase delay introduced by the sample in through transmission acts as a contrast agent. Hence, the optical thickness measurable by DH imaging is an integral information, i.e. the sum of all the contributions experienced by the coherent light during its passage through the sample. In order to decouple the refractive index from the physical thickness and to resolve its distribution along the optical axis, tomography exploits multiple recordings, probing the sample from different angles and combining the corresponding phase-contrast maps [7,8]. Various schemes have been proposed to minimize the number of sampling angles and to make the recording stage faster in order to match the requirements and time constraints imposed by real biological problems. Here we show the recent advances of in-flow holographic tomography, which exploits a controlled induced rotation of the sample inside the microfluidic channel to probe it from different view angles with no mechanical rotation of the source beam [8,9]. We introduce an effective algorithm to recover from the recorded phase maps the set of angles required as input of the optical projection tomography algorithm [7-9]. We show the application of holographic flow tomography to the characterization of different cancer cells [10], namely breast cancer cells, ovarian cancer cells and neuroblastoma. We also discuss different possibilities of Lab-on-a-Chip design and flow engineering that allow us to induce controlled rotations while maintaining the high-throughput nature of DH microscopy [9,11,12]. In the next future, the large amount of data obtainable by this approach will be used to train a neural network devoted to classify CTCs, distinguishing them from the other components of a blood stream.
关键词： liquid biopsy,cancer cells,microfluidics,circulating tumor cells,holographic tomography,Lab-on-a-Chip,digital holography
更新于2025-09-16 10:30:52
-
[IEEE 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Sao Paulo, Brazil (2019.10.7-2019.10.9)] 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Production of a microfluidic random laser using ultrashort laser pulses
摘要： A random rhodamine laser system is produced on board of a femtosecond laser machined microfluidic system. When pumped by a nanosecond pulsed laser beam at 532 nm, laser emission at 610 nm is observed together with the linewidth narrowing typical of random lasers. The system can be easily integrated as an optofluidic component into microfluidic circuits for assessment of optical parameters on board of the lab-on-chip.
关键词： lab-on-chip,random lasers,microfluidics
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Bulk Power System Dynamics with Varying Levels of Synchronous Generators and Grid-Forming Power Inverters
摘要： The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These microhydraulic actuators use a high surface-to-volume ratio to deliver high power at a relatively low voltage with an energy conversion efficiency of over 65%. The capillary pressure generated grows linearly with shrinking capillary diameter, as does the frequency of actuation. We present the pressure, frequency, and power scaling properties of these actuators and demonstrate that power density scales up as the inverse capillary diameter squared, leading to high-efficiency actuators with a strength density exceeding biological muscle. Two potential applications for microhydraulics are also demonstrated: soft-microrobotics and energy harvesting.
关键词： microsystems,electrocapillary,soft robotics,PDMS,actuator,energy conversion,microfluidics,electrowetting,energy harvesting,porous materials,Microhydraulics,microrobotics
更新于2025-09-16 10:30:52
-
Solid State Optical Microlasers Fabrication via Microfluidic Channels
摘要： In this paper, we propose the use of a microfluidic channel with flow focusing technique to fabricate solid state polymeric microlasers to precisely control sizes for mass production. Microlasers are made from a solution of UV curable polymer, namely polyethylene glycol diacrylate (PEGDA) with a molecular weight of 700 and rhodamine 6G laser dye at two different volumetric ratios (polymer to dye) of 4:1 and 2:1, respectively, which are used as the dispersed phase. A reservoir filled with liquid polydimethylsiloxane (PDMS) was used to cure the microlasers via UV lamp. A microchannel made of (PDMS) and size of 200 μm was used in this paper; mineral oil was selected as the continuous phase. Two experiments are conducted by fixing the pressure flow for the dispersed phase to 188 mbar and 479.9 mbar, respectively. In both experiments, the pressure of the continuous phase (mineral oil) was varied between 1666.9 mbar and 1996.9 mbar. The measurement of the fabricated microlasers’ size was performed with the aid of the MATLAB Image Processing Toolbox by using photographs taken with a CMOS camera. The tunability of the highest size, ranging from 109 μm to 72 μm, was found for the PEGDA to dye ratio of 2:1 (188 mbar) and average standard deviation of 1.49 μm, while no tunability was found for the 4:1 ratio (188 mbar). The tunability of the microlaser’s size, ranging from 139 μm to 130 μm and an average standard deviation value of 1.47 μm, was found for the 4:1 ratio (479.9 mbar). The fabricated microlasers presented a quality factor Q of the order 104, which is suitable for sensing applications. This technique can be used to control the size of the fabrication of a high number of solid state microlaser based UV polymers mixed with laser dyes.
关键词： microlasers,PEGDA,microfluidics
更新于2025-09-16 10:30:52
-
On-demand Milifluidic Synthesis of Quantum Dots in Digital Droplet Reactors
摘要： Colloidal quantum dots (QDs) offer dramatic potential due to their size-dependent optical properties. Lack of facile synthesis methods for precise and reproducible size and composition, however, present an extant barrier to their widespread use. Here we report the use of droplet microfluidics for the simple and highly reproducible synthesis of cadmium sulfide (CdS) and cadmium selenide (CdSe) QDs without the use of harsh solvents and in ambient conditions. Our approach uses a liquid-liquid barrier between two immiscible liquids to generate a digital droplet reactor. This reaction droplet is easily controlled and manipulated and offers enhanced mixing when coupled to a helical mixer, resulting in a significant reduction in size distribution compared to benchtop procedures. Furthermore, QD characteristics have modeled and predicted based on the parameters of the microfluidic device. We believe this method overcomes the current manufacturing challenges with synthesizing nanostructures, which is required for the next generation of nanosensors.
关键词： CdS,CdSe,quantum dots,microfluidics,nanosensors
更新于2025-09-12 10:27:22
-
[IEEE 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - Seoul, Korea (South) (2019.1.27-2019.1.31)] 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - Rapid Multi-Material Direct Laser Writing
摘要： The additive manufacturing or “three-dimensional (3D) printing” technology direct laser writing (DLW) offers a level of geometric versatility at submicron scales that yields substantial benefits for fields including photonics, meta-materials, and 3D cell biology. A key limitation of DLW, however, stems from the difficulties in 3D printing micro/nanoscale structures with more than a single material. Specifically, producing multi-material components requires laborious and time-intensive protocols for manual substrate/material processing and alignment to maintain structural continuity among distinct photomaterials. To overcome these challenges, here we introduce a “rapid multi-material DLW (RMM-DLW)” strategy that enables 3D nanostructured features comprised of multiple, fully integrated photomaterials to be additively manufactured with unprecedented speed and accuracy. This approach leverages an impermanent elastomeric bonding technique to achieve temporary microchannels through which distinct photomaterials can be serially loaded, photopolymerized, and developed; the elastomer can be removed thereafter. Preliminary RMM-DLW results revealed a 74% reduction in fabrication time, with a multi-material alignment accuracy of 0.14±0.17 μm (?X) and 0.20±0.15 μm (?Y) – an improvement of up to one order of magnitude over conventional multi-material DLW. In combination, these results suggest a promising pathway to achieve fundamentally new classes of multi-material, and in turn, multi-functional 3D nanostructured systems.
关键词： additive manufacturing,direct laser writing,microfluidics,multi-material,3D printing
更新于2025-09-12 10:27:22
-
Effect of Cyano Substitution on Conjugated Polymers for Bulk Heterojunction Solar Cells
摘要： Portable and autonomous pumps are in critical demand for low-cost point-of-care testing (POCT) applications in microfluidic fields. In microfluidic laboratories, commercial pumps (e.g., syringe pumps, pressure pumps, or peristaltic pumps) are widely used for precise fluid delivery, however they can’t be integrated into miniaturized microfluidic devices due to their bulky sizes and high costs. Here, we propose a portable plug-and-play syringe pump with compression force, and constant flow autoregulation is realized through the microfluidic flow regulatory chip which contains three passive valves. Importantly, the liquid flow rate through regulatory chip in the pump. This feature has been used for providing steady fluid infusions for passive sample mixing in a T-junction microfluidic mixer or high efficiency particle separation in an inertial microfluidic chip. We envision that the self-sufficient and portable plug-and-play syringe pump will facilitate the miniaturization of microfluidic systems which will shed light on the large-scale application of microfluidic technologies.
关键词： Passive valve,Flow control,Plug-and-play pump,Flow mixing,Particle separation,Microfluidics
更新于2025-09-12 10:27:22