Fabrication of 3D Controlled in vitro Microenvironments

Berrin Ozdil,Sevgi Onal,Tugce Oruc,Devrim Pesen Okvur

doi:10.1016/j.mex.2014.06.003

Abstract

Microfluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments. Thus there is an ever increasing interest in their fabrication. Our goal is to construct three dimensional (3D) Controlled in vitro Microenvironments (CivMs) that mimic the in vivo microenvironments. Here, we present our optimized fabrication method that works for various lab-on-a-chip designs with a wide range of dimensions. The most crucial points are:•While using one type of SU-8 photoresist (SU-2075), fine tuning of ramp, dwell time, spin speed, durations of soft bake, UV exposure and development allows fabrication of SU-8 masters with various heights from 40 to 600μm.•Molding PDMS (polydimethylsiloxane) at room temperature for at least two days instead of baking at higher temperatures prevents not only tears and bubbles in PDMS stamps but also cracks in the SU-8 master.•3D nature of the CivMs is ensured by keeping the devices inverted during gel polymerization.

Highlights

Microfluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments
The devices provide physiologically relevant settings for cell biology experiments [3,4,5,6,7,8]. Such advantages have resulted in an increased interest in the methodological details of fabrication of lab-on-a-chips [9,10,11]
SU-8 is widely used for fabrication of masters that are in turn used for both 2D and 3D structures of interest

Summary

GRAPHICAL ABSTRACT

ABSTRACT Microfluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments. The devices provide physiologically relevant settings for cell biology experiments [3,4,5,6,7,8]. Such advantages have resulted in an increased interest in the methodological details of fabrication of lab-on-a-chips [9,10,11]

UV lithography

PDMS molding

Balance Vacuum desiccator

Preparation of PDMS molds