Review
Cell Biology
Nicole M. E. Valle, Mariana P. Nucci, Arielly H. Alves, Luiz D. Rodrigues, Javier B. Mamani, Fernando A. Oliveira, Caique S. Lopes, Alexandre T. Lopes, Marcelo N. P. Carreno, Lionel F. Gamarra
Summary: This systematic review analyzed the development and functionality of microfluidic concentration gradient generators (CGGs) for toxicological evaluation. The majority of articles focused on the fabrication methods, characteristics of the CGGs, biological models, and evaluation techniques. Soft lithography using PDMS material and the Christmas tree CGG design were popular choices. Imaging and microscopy techniques were commonly used for evaluating the toxic effects. CGGs showed advantages over other techniques and were applicable to various biological models.
Article
Chemistry, Analytical
Yu-Hsun Wang, Chi-Hung Ping, Yung-Shin Sun
Summary: This study reports a rationale for designing Christmas-tree-like MGGs to achieve uniform flow rates across all outlets. The simulation results suggest that the lengths of vertical channels should be as long as possible compared to horizontal channels, and modifying the partition of horizontal channels is more effective than elongating the lengths of vertical channels. This design rationale will help construct optimal MGGs for cell-based applications including chemotherapy, drug resistance, and drug screening.
Article
Computer Science, Interdisciplinary Applications
Seong Hyeon Hong, Jung-Il Shu, Junlin Ou, Yi Wang
Summary: A GPU-enabled design framework is presented to automate the global optimization process of microfluidic concentration gradient generators. The framework utilizes a physics-based component model for simulation and incorporates a genetic algorithm for optimization. The results demonstrate the potential of applying microfluidic design automation on the edge-computing platform in laboratory environments.
ENGINEERING WITH COMPUTERS
(2023)
Article
Optics
Xufend Jing, Guihong Qin, Peng Zhang
Summary: This study proposes a multi-functional metamaterial absorber based on doped silicon, which achieves broadband absorption through resonance and impedance matching, and precise amplitude control by controlling the pump luminous flux. By replacing the medium-doped silicon material with highly doped silicon material and combining it with microfluidic control, a high sensitivity sensor is realized. Experimental verification demonstrates the potential of this absorber in sensing applications.
PHOTONICS RESEARCH
(2022)
Article
Engineering, Biomedical
Jaehoon Kim, Hyejin Park, Hyunho Kim, YongTae Kim, Hyun Jeong Oh, Seok Chung
Summary: Tumors create interstitial flow (IF), which allows soluble substances from cancer cells to be transported towards the tumor stroma. Researchers have designed a microfluidic device that mimics one-directional flow of IF to investigate how cancer cells activate and differentiate stromal cells.
ACTA BIOMATERIALIA
(2022)
Article
Engineering, Electrical & Electronic
Ying-Hsuan Chiu, Chia -Yu Cho, Jiun- Hsu, Sheng-Feng Hung, Chih-Lin Huang, Yao-Joe Yang
Summary: This paper presents a methodology for synthesizing concentration gradient generators (CGGs) with arbitrary concentration profiles. The synthesized CGGs employ a one-step-dilution microfluidic network and inexpensive multi-barrel syringe pumps. The proposed design has the potential for high throughput and a wide range of input flowrates. The synthesized CGGs were simulated, validated, fabricated, and implemented, and the results show that they can consistently generate precise concentration gradients for various types of concentration profiles.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Computer Science, Interdisciplinary Applications
Haizhou Yang, Seong Hyeon Hong, Yu Qian, Yi Wang
Summary: This paper presents a multi-fidelity surrogate-based optimization method for accurate and efficient design of microfluidic concentration gradient generators. A cokriging-based multi-fidelity surrogate model is constructed to combine data with varying fidelities and computational costs, and an adaptive sampling approach is developed to accelerate the optimization process. The results demonstrate that the proposed method achieves faster convergence and better designs compared to the existing methods.
ENGINEERING COMPUTATIONS
(2023)
Article
Polymer Science
Sang Ik Lee, Yoon Young Choi, Seong Goo Kang, Tae Hyeon Kim, Ji Wook Choi, Young Jae Kim, Tae-Hyung Kim, Taewook Kang, Bong Geun Chung
Summary: A microfluidic-based droplet system was developed to generate uniform 3D tumor spheroids for drug screening applications. The system allowed high-throughput generation of spheroids with various cellular ratios, providing a potentially powerful tool for anti-cancer drug analysis.
Article
Chemistry, Analytical
Paulo Henrique Maciel Buzzetti, Maiara Mitiko Taniguchi, Nayara de Souza Mendes, Renata Correa Vicentino, Jean Halison de Oliveira, Bento Pereira Cabral Junior, Marcos de Souza, Johny Paulo Monteiro, Emerson Marcelo Girotto
Summary: In this study, a microfluidic device based on serial dilution was developed to generate nonlinear concentration gradients for dyes and biomolecules. The device was mathematically described and statistically validated, showing reproducibility in experiments and agreement with computational fluid dynamics simulation. The applicability of the device was demonstrated by coupling it with a surface plasmon resonance (SPR) biosensor, and the results were validated by fluorescence emissions.
Article
Chemistry, Analytical
Yufang Liu, Jiao Li, Jiasheng Zhou, Xue Liu, Huibing Li, Yao Lu, Bingcheng Lin, Xiaojie Li, Tingjiao Liu
Summary: Angiogenesis was assessed using a microfluidic chip, showing VEGF as a key determinant for vascular sprouting initiation. Different isoforms of VEGF displayed varying effects on sprout length and number, vessel perfusion, and connectivity, with VEGF(165) demonstrating the highest capacity to induce vascular sprouting and functional vessel formation.
Article
Biochemical Research Methods
Shital Yadav, Pratik Tawade, Ketaki Bachal, Makrand A. A. Rakshe, Yash Pundlik, Prasanna S. S. Gandhi, Abhijit Majumder
Summary: In this study, a microfluidic concentration gradient generator (mu CGG) was developed using a non-conventional photolithography-less method. The fabricated device showed advantages over conventional photolithography, such as easy channel layout and cost-effectiveness, and demonstrated its potential for various biological and non-biological applications.
Article
Biophysics
Wenyi Zeng, Peng Chen, Shunji Li, Qiuyue Sha, Pengjie Li, Xuemei Zeng, Xiaojun Feng, Wei Du, Bi-Feng Liu
Summary: The article introduces a hand-powered vacuum-driven microfluidic device that can rapidly generate concentration gradients of different antibiotics for antibiotic susceptibility testing. The device is easy to operate, with advantages such as high throughput, cost efficiency, and shortened detection time.
BIOSENSORS & BIOELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Florian Huet, Vincent Boitier, Lionel Seguier
Summary: This article presents the design strategy and experimental validation of a battery-free power supply for wireless sensor nodes based on vibration energy harvesting. By adjusting the resonance frequency and using supercapacitors for energy storage, the power supply is capable of providing stable current for long-term operation in an industrial environment.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Gao Weizhuo, Jing Weixuan, Du Yanrui, Li Zehao, Han Feng, Zhao Libo, Yang Zhaochu, Jiang Zhuangde
Summary: In this paper, microfluidic voltage generation based on reduced graphene oxide (rGO) was fabricated and the effect of rGO concentration and volume flow rate on the performance of the microfluidic voltage generation was studied. The relationship between Na+ ion concentration, induced potential, and microfluidic voltage generation was established using the Nernst-Planck equation. Additionally, the relationship between rGO concentration, surface morphology of rGO membranes, Na+ ion concentration, and induced potential of the microfluidic voltage generation was established. The results provide insights for the fabrication and performance optimization of carbon-based microfluidic voltage generations, as well as improvements in behavior of microfluidic channel-based photo-degradation reactors, ion sensing devices, and electrochemical glucose sensors.
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2023)
Article
Chemistry, Multidisciplinary
Jingjing Kuang, Wei Sun, Min Zhang, Lu Kang, Shenglong Yang, Hongyang Zhang, Yuerong Wang, Ping Hu
Summary: In this study, a three-dimensional cell co-cultured microfluidic chip was designed to simulate the complex tumor microenvironment. The chip consisted of multiple channels for cell culture, simulation of extracellular matrix, and the supply of nutrients and bioactive factors. The results showed that the co-culture of Hepa1-6 cells, hypoxia, and TGF-beta 1 promoted the migration of JS-1 cells. Additionally, activated JS-1 cells induced epithelial-mesenchymal transition in co-cultured Hepa1-6 cells, leading to increased secretion of TGF-beta 1.
CHINESE CHEMICAL LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Rahul Karyappa, Terry Ching, Michinao Hashimoto
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Chemistry, Multidisciplinary
Kumari Priti Sinha, Sudip Das, Rahul Bapusaheb Karyappa, Rochish M. Thaokar
Article
Chemistry, Applied
Aakanksha Pant, Amelia Yilin Lee, Rahul Karyappa, Cheng Pau Lee, Jia An, Michinao Hashimoto, U-Xuan Tan, Gladys Wong, Chee Kai Chua, Yi Zhang
Summary: The research focuses on enhancing the nutritional value and reducing costs of 3D food printing using fresh vegetables to meet the needs of dysphagic diets.
FOOD HYDROCOLLOIDS
(2021)
Article
Chemistry, Analytical
Sindhu Vijayan, Pravien Parthiban, Michinao Hashimoto
Summary: PolyJet (TM) 3D printers are commonly used for fabricating microfluidic molds, but the printed microstructures exhibit deviations in both lateral and vertical dimensions. The spreading of resin leads to larger width than designed, affecting the reproduction of intended heights in narrow-designed microstructures. Mathematical models developed in this study can accurately predict the dimensional deviations and may be useful for designing and fabricating microstructures using PolyJet printers.
Article
Chemistry, Analytical
James S. Ng, Michinao Hashimoto
Summary: This paper introduces a method of utilizing FDM printing to fabricate paper-based analytical devices with three-dimensional features, using two types of thermoplastics to overcome limitations related to organic solvents in traditional PADs. The study validated the capability and potential applications of 3D-PADs in holding increased amounts of liquid samples and demonstrated colorimetric assays for organic solvent-based reactions.
Article
Nanoscience & Nanotechnology
Rahul Karyappa, Wei Huang Goh, Michinao Hashimoto
Summary: Flexible core-shell 3D structures are crucial for the development of soft sensors and actuators. However, fabricating such structures with internal architectures using liquid precursors remains challenging. This study proposes a unique approach using direct ink writing (DIW) 3D printing in a three-phase system to overcome this limitation. By carefully selecting the rheological properties and flow rates of the three phases, this method allows the formation of droplets consisting of core liquids distributed along the printed filaments. This technique offers a simple route to fabricate 3D structures of a soft elastomeric matrix with embedded channels, which is valuable for the fabrication of flexible wearable devices and soft robotic components.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Jing Cao, Bo Yuan, Na Gong, Tzee Luai Meng, Siew Lang Teo, Anna Marie Yong, Xikui Zhang, Ming Lin, Rahul Karyappa, Lei Zhang, Chee Kiang Ivan Tan, Ady Suwardi, Qiang Zhu, Hongmei Jin, Christopher M. Harvey, Simon Wang, Hongfei Liu
Summary: Au thin films, up to h ≈ 90 nm, deposited by direct current sputtering at room temperature, were studied to investigate the effect of coating thickness on film blistering. Blisters were found to nucleate at the Au/NBSC interface using transmission electron microscopy. Statistical analysis showed that the blister diameters increase while their density decreases with increasing h. However, the height-to-diameter ratios of the blisters remain constant and independent of h.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Na Gong, Hwee Leng Seng, Hongmei Jin, Jing Cao, Tzee Luai Meng, Siew Lang Teo, Rahul Karyappa, Xikui Zhang, Lei Zhang, Ming Lin, Chee Kiang Ivan Tan, Ady Suwardi, Qiang Zhu, Hongfei Liu
Summary: The deposition of thin films has various multidisciplinary applications, and residual adsorptions play a crucial role in low-vacuum depositions. The mechanisms of thin film blistering are complex and comprehensive.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Rahul Karyappa, Wei Huang Goh, Michinao Hashimoto
Summary: Flexible core-shell 3D structures are crucial for the development of soft sensors and actuators. This study introduces a novel approach using direct ink writing (DIW) 3D printing in a three-phase system to fabricate flexible 3D objects with internal architectures. By combining low-viscosity polysiloxane resin as shell inks with a coaxially extruded core liquid, the researchers were able to overcome the difficulties of maintaining printed structures and successfully create core-shell 3D structures with perfusable channels.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Rahul Karyappa, Michinao Hashimoto
Summary: The unique approach of freeform polymer precipitation (FPP) allows for 3D printing of thermoplastics in embedding media, demonstrating controlled internal porosity. By optimizing printing conditions, vertical and lateral attachments of printed inks can be ensured, leading to the fabrication of porous 3D objects. FPP offers a simple route to creating 3D freeform structures of thermoplastics with various properties.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Engineering, Biomedical
Justin Jia Yao Tan, Cheng Pau Lee, Michinao Hashimoto
INTERNATIONAL JOURNAL OF BIOPRINTING
(2020)
Article
Chemistry, Multidisciplinary
Cheng Pau Lee, Rahul Karyappa, Michinao Hashimoto
Article
Chemistry, Multidisciplinary
James S. Ng, Michinao Hashimoto