Photolithography Lift-off
Photolithography Lift-off - Related Videos
07:44
Microfabrication via Photolithography
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2023
The fabrication of BioMEM devices is often done using a microfabrication technique called photolithography. This widely used method utilizes light to transfer a pattern onto a silicon wafer, and provides the basis for the fabrication of many types of BioMEM devices. This video presents the photolithography technique, shows how the process is performed in the cleanroom, and introduces some applications of the process.
01:23
Lift
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2025
Lift is a fundamental aerodynamic force that acts perpendicular to the direction of airflow. It plays a central role in achieving and sustaining flight and in stabilizing various vehicles. Lift primarily originates from pressure differences created across surfaces, such as an airfoil. A lower pressure region forms above the wing, while a higher pressure region forms below it, generating an upward force. This differential results from the shape and orientation of the airfoil, enabling the wing...
10:18
Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices
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Cited by 26 •
2017
Multilayer microfluidic devices often involve the fabrication of master molds with complex geometries for functionality. This article presents a complete protocol for multi-step photolithography with valves and variable height features tunable to any application. As a demonstration, we fabricate a microfluidic droplet generator capable of producing hydrogel beads.
09:18
Clark Y-14 Wing Performance: Deployment of High-lift Devices (Flaps and Slats)
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2023
Source: David Guo, College of Engineering, Technology, and Aeronautics (CETA), Southern New Hampshire University (SNHU), Manchester, New Hampshire A wing is the major lift-generating apparatus in an airplane. Wing performance can be further enhanced by deploying high-lift devices, such as flaps (at the trailing edge) and slats (at the leading edge) during takeoff or landing. In this experiment, a wind tunnel is utilized to generate certain airspeeds, and a Clark Y-14 wing with a flap and slat...
08:15
Polymeric Microneedle Array Fabrication by Photolithography
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Cited by 24 •
2015
Here, we present a protocol describing a mold-free fabrication process of the polymeric microneedles by photolithography.
FAQs
The photoresist acts as a temporary pattern-forming layer rather than a permanent part of the device. Light exposure through a mask and subsequent development determine which substrate regions remain covered and which become accessible. Because the resist is later dissolved, material deposited over it is removed, allowing the final pattern to be formed without etching the substrate directly.
Mask exposure transfers selected feature locations into the photoresist, while development reveals the regions specified by that exposure and resist response. These opened areas identify where the substrate can receive the deposited material. The resulting pattern therefore depends on the relationship between the mask-defined exposure and the developed resist structure, which supports controlled microscale dimensions.
Lift-off can create a patterned film without using an etching step on the underlying substrate. This distinction matters in bioengineering devices when direct etching could damage underlying materials. The approach is therefore useful for building microscale structures on substrates or existing layers that require protection while still receiving defined metal or other functional-material patterns.
Deposition coats both the photoresist and the exposed substrate. Material resting on the resist is removed when the sacrificial layer dissolves, whereas material contacting the exposed substrate remains as the intended feature. This difference converts the temporary resist pattern into a permanent material pattern and determines which regions contribute to the finished device.
The workflow begins by preparing a substrate with photoresist, defining features through masked light exposure, and developing the resist to expose selected regions. A metal or other functional material is then deposited across the patterned surface. Finally, dissolving the resist removes the unwanted overlying material, leaving the deposited features aligned with the developed pattern.
In bioengineering, the method can produce electrodes, microfluidic features, biosensor surfaces, and cell-guiding patterns. These structures support lab-on-a-chip devices, neural interfaces, and other microscale systems that require spatially controlled materials. Its value comes from combining patterned fabrication with the ability to avoid direct etching of potentially vulnerable underlying materials.
The process provides patterned thin films and other functional-material features with controlled dimensions. Depending on the design, these patterns can serve electrical, fluidic, sensing, or cell-guidance functions. Such control helps integrate multiple microscale elements into systems including biosensors, lab-on-a-chip platforms, neural interfaces, and related devices where feature placement is important.