Review Type: Soft Lithography & microfabrication

Circular channel fabrication in microfluidic devices Written by Oore-ofe Olumuyiwa Akeredolu Published September 28th 2020 Contact: partnership@elvesys.com, Elvesys SAS, 172 Rue de Charonne 75011 Paris Circular channels in microfluidic devices are complex structures and their fabrication requires specific techniques not commonly implemented in mass production. Therefore, it is today nearly impossible to find microfluidic devices with … Continued

Soft lithography: SU-8 coating In soft lithography, the fabrication of a mold, often made in SU-8, is required for replicating PDMS microfluidic structures. For the fabrication of this SU-8 master, a standard photolithography process is commonly used. Therefore, a first key concern is to apply a coating of SU-8 photoresist layer on a silicon wafer, … Continued

Soft lithography: SU-8 baking Equipement and protocols for heating SU-8 molds Replicating PDMS-based structures first requires the fabrication of a SU-8 master mold that will serve as a patterned template for PDMS casting. During the fabrication of the SU-8 master, which is usually based on standard photolithography, the film of SU-8 photoresist must be baked … Continued

How to succeed with your SU-8 photoresist UV exposure? The SU-8 photoresist UV exposure The aim of the SU-8 photoresist UV exposure is to initiate the cross linkage by the activation of the PAC (PhotoActiv Component) in some parts of the SU-8 photoresist. This activation will change the local properties of the SU-8 which after baking … Continued

How to succeed with SU-8 photoresist baking SU-8 photoresist baking: pre-bake, soft bake and hard bake The SU-8 photoresist baking is carried out two or three times during the whole process and each bake has different meanings. The first photoresist bake is called soft bake; it’s done just after the spin coating of the SU-8 photoresist. … Continued

How to succeed with your SU-8 photoresist spin coating Introduction The coat of SU-8 photoresist on a substrate can be done by several techniques. The most used is spin coating which consists in putting a puddle of SU-8 photoresist on a rotated substrate. The rotation speed, the acceleration and the SU-8 photoresist viscosity will define the thickness of … Continued

How to make a spin-coated PDMS layer? Introduction A thin layer of PDMS is called a PDMS membrane. The PDMS membrane has several properties which make it quite valuable. Thanks to the permeability of PDMS, the membrane can be used to exchange gas or small molecules between two liquids or a gas and a liquid … Continued

How to make an epoxy SU-8 mold? The SU-8 mold fabrication process: tips and tricks To perform PDMS soft lithography, you need to use a mold. The most commun and used molds are certainly the epoxy resin SU-8 molds. Every year many laboratories begin a microfluidic activity and sometimes not with the good equipment or methodology. This … Continued

How to make a PDMS lithography replication from a SU-8 mold The PDMS lithography replication process: tips and tricks The PDMS is a polymer widely used in microfluidics to make devices such as lab on chip. Every year many laboratories begin a microfluidic activity and sometimes not with the good equipment or methodology, this review aims … Continued

Introduction to PDMS soft-lithography and polymer molding for microfluidics  What is PDMS soft lithography? Soft lithography can be viewed as a complementary extension of photolithography. Originally, standard photolithography was mainly developed to deal with semiconductors used in the microelectronics industry. Photolithography is inherently well adapted to process photoresists. Thereby, most microfluidic devices still rely on … Continued