Integrated biocompatible 3D printed isoporous membranes with 7 μm pores.

In this work, we present a new 3D printing technique that enables the realization of native digital micro-mirror device (DMD) resolution in negative features of a 3D printed part without improving 3D printer hardware and demonstrate the fabrication of fully integrated, biocompatible isoporous membranes with pore sizes as small as 7 μm. We utilize this technique to construct a microfluidic device that mimics an established organ-on-a-chip configuration, including an integrated isoporous membrane. Two cell populations are seeded on either side of the membrane and imaged as a proof of concept for other organ-on-a-chip applications.

Biocompatible High-Resolution 3D-Printed Microfluidic Devices: Integrated Cell Chemotaxis Demonstration.

We demonstrate a method to effectively 3D print microfluidic devices with high-resolution features using a biocompatible resin based on avobenzone as the UV absorber. Our method relies on spectrally shaping the 3D printer source spectrum so that it is fully overlapped by avobenzone's absorption spectrum. Complete overlap is essential to effectively limit the optical penetration depth, which is required to achieve high out-of-plane resolution.

3D-Printed Microfluidic One-Way Valves and Pumps.

New microfluidic lab-on-a-chip capabilities are enabled by broadening the toolkit of devices that can be created using microfabrication processes. For example, complex geometries made possible by 3D printing can be used to approach microfluidic design and application in new or enhanced ways. In this paper, we demonstrate three distinct designs for microfluidic one-way (check) valves that can be fabricated using digital light processing stereolithography (DLP-SLA) with a poly(ethylene glycol) diacrylate (PEGDA) resin, each with an internal volume of 5-10 nL.

Vat photopolymerization 3D printed microfluidic devices for organ-on-a-chip applications.

Organs-on-a-chip, or OoCs, are microfluidic tissue culture devices with micro-scaled architectures that repeatedly achieve biomimicry of biological phenomena. They are well positioned to become the primary pre-clinical testing modality as they possess high translational value. Current methods of fabrication have facilitated the development of many custom OoCs that have generated promising results.

Spatially and optically tailored 3D printing for highly miniaturized and integrated microfluidics.

Traditional 3D printing based on Digital Light Processing Stereolithography (DLP-SL) is unnecessarily limiting as applied to microfluidic device fabrication, especially for high-resolution features. This limitation is due primarily to inherent tradeoffs between layer thickness, exposure time, material strength, and optical penetration that can be impossible to satisfy for microfluidic features. We introduce a generalized 3D printing process that significantly expands the accessible spatially distributed optical dose parameter space to enable the fabrication of much higher resolution 3D components without increasing the resolution of the 3D printer.

Post-fabrication tuning of microring resonators using 3D-printed microfluidics.

We demonstrate a method of tuning the resonant frequencies of silicon microring resonators using a 3D-printed microfluidic chip overlaid directly on the photonic circuit with zero energy consumption following the initial tuning. Aqueous solutions with different concentrations of NaCl are used in experimentation. A shift of a full free spectral range is observed at a concentration of 10% NaCl.

Self-Sustaining 3D Thin Liquid Films in Ambient Environments.

Thin liquid films (TLF) have fundamental and technological importance ranging from the thermodynamics of cell membranes to the safety of light-water cooled nuclear reactors. The creation of stable water TLFs, however, is very difficult. In this paper, the realization of thin liquid films of water with custom 3D geometries that persist indefinitely in ambient environments is reported.