Liwei Lin (Advisor)

Research Advised by Professor Liwei Lin

Lin Group:  List of Projects | List of Researchers

BPN796: Low Reynolds Number Mixing using 3D Printed Microfluidics

Casey C. Glick
Eric C. Sweet
Kevin A. Korner
Yash Attal
Gregory Slatton
Ryan Jew
Josh Chen
2016

Mixing in microfluidic devices has long presented challenges due to the lack of significant turbulence at low Reynolds numbers. Although ample theoretical work has demonstrated methods to enhance microfluidic mixing (e.g., increasing vorticity, arranging chaotic flow profiles), many of these methods are difficult to achieve in practical microfluidic devices, requiring 2D approximations to fully 3D mixing enhancements. In this work, we will show that various designs for enhanced mixing are easily achievable using 3D printing. We will compare the performance of several different mixer...

BPN706: Single-Layer Microfluidic Gain Valves via Optofluidic Lithography

Casey C. Glick
Kevin Korner
2016

This project aims to create single-layer microfluidic gain valves for use in microfluidic devices. Autonomous microfluidic devices are essential for the long-term development of versatile biological and chemical platforms; however, the challenges of creating effective control mechanisms – e.g., the need for variable pressure sources, signal degradation in cascaded devices, and multi-stage manufacture methods – have proven considerable. Using in situ optofluidic lithography, we develop a single-layer pressure-based valve system with a static gain greater than unity. We will...

BPN787: 3D-Printed Molds for Rapid Assembly of PDMS-based Microfluidic Devices

Casey C. Glick
2016

In this work, we demonstrate the use of 3D-printed molds for fabricating PDMS-based microfluidic devices. 3D Printing allows for the fabrication of molds that are not monolithic in structure, and therefore represents a significant improvement over the capabilities of standard soft lithography; with 3D-printed molds, we can fabricate most features commonly generated by soft lithography in addition to formerly difficult features such as domes and variable-sized channels. Furthermore, we demonstrate that this technique can be used to generate microfluidic devices molded on both sides -...

BPN841: Fast-Response Silver Passive Temperature Sensor via Electro-Hydrodynamic (EHD) Printing Method

Hyung-Seok Jang
2016

Electro-Hydrodynamic (EHD) Printing based direct write method has been demonstrated that the efficient fabrication process for the fast-response and super-thin silver (Ag) passive temperature sensor. For the direct write Ag passive temperature sensor, biological polymer was applied for efficient Ag nanostructure formation, and the EHD Printer directly eject and deposit this Ag precursor ink on the substrate. During annealing process this Ag passive sensor rapidly produce the 2D nanoparticles from the air/water interface and directly sintered to Ag thin film patterns in 200oC. This...

BPN845: 3D Printed Finger-Powered Microfluidic Pump and Mixer

Eric C. Sweet
Ilbey Karakurt
Rudra R. Mehta
2016

Low-powered microfluidic systems have been demonstrated in a variety of point-of-care biomedical diagnostic applications; however, the potential for the widespread commercial applicability of this technology, the requirement for being portable, disposable and inexpensive, is greatly hindered by the nearly-ubiquitous need for bulky and expensive externally- powered pressure sources needed to pump fluids through such devices. Furthermore, as advanced additive manufacturing techniques such as micro/nano-scale 3D printing are becoming more widely used in BioMEMS manufacturing,...

BPN800: Solution Processed Oxide Materials

Hyun Sung Park
2017

Recently there has been growing interest in transparent conductive oxides(TCOs) and oxide semiconductors, they are key components for future transparent electronics devices. But there are needs for finding new TCOs and oxide semiconductors because the Indium and Galium are expensive rare earth material and the price is still increasing. Also, conventional vacuum based process is a problem for large scale and complicated geometry devices. In this project, I introduced new TCO material(ATO) and oxide semiconductor for the future transparent electronics devices by using solution process...

BPN672: Solar Hydrogen Production by Photocatalytic Water Splitting

Emmeline Kao
Neil Ramirez
2018

Hydrogen is a promising, environmentally-friendly fuel source for replacing fossil fuels in transportation and stationary power applications. Currently, most hydrogen is produced from non-renewable sources including natural gas, oil, and coal. Photoelectrochemical (PEC) water splitting is a new renewable energy technology that aims to generate hydrogen from water using solar energy. When light is absorbed by the photocatalyst, an electron-hole pair is generated that interacts with water molecules in a surface reduction-oxidation reaction to decompose the water into hydrogen and...

BPN885: Transition Metal Carbide-Based Membrane for Solar-Water Energy Harvesting

Xining Zang
2018

Solar-enabled evaporation is a solar-energy-harvesting technology that can be used in modern power plants, chemical plants, and seawater desalination plants. A new type of nanostructured laterally assembled two-dimensional carbide (MoC0.66) membrane is manufactured using CO2 laser ablation and vacuum filtration. With high absorption efficiency in a wide spectrum range from visible light to IR, the membrane functions as photo-absorber. With a carbide membrane on top of water, the evaporation under energy input is greatly promoted. Meanwhile, evaporation enabled water flow in the...

BPN742: Hash Environmental Energy Storage Based on Two-Dimensional Carbide Materials

Xining Zang
Minsong Wei
2018

MXENE carbide with rich surface -OH, -OOH functional group generally cannot survive higher than 200 oC, and structure collapse with surface oxidation will be critical for energy storage. However, 2d- like nanocrystalline assembled carbide with “purer” carbide phase will provide better temperature and chemical resilience. Highly conductive, capacitive 2d-like carbide hybrid electrodes with high surface area and strong ion intercalation will provide solutions for extreme condition energy storage with high capacitance/capacity.

Project end date: 08/06/18

BPN886: 2D Carbides as a New Family of Gas Sensing Materials with Wide Working Temperature Range

Xining Zang
Niravkumar Joshi
2018

Some of the 2d and 2d-like carbide exhibit tunable band structure with relatively high conductivity, which provides sensing function for dopants such as gas molecules. 2d-like carbide also has limited phase change induced nanostructure aggregation. With up to 1000K thermal stability, such carbides will be a better fit than other oxide and nitride materials in higher temperature sensing. For certain gases that require combustion sensing, nanostructure 2d-like carbides will be much stable and reliable. 2d-like Molybdenum carbide is three times more sensitive than graphene in response...