3D Printing, Ink Casting and Micromachined Lamination (3D PICLμM): A Makerspace Approach to the Fabrication of Biological Microdevices

Abstract

We present a novel benchtop-based microfabrication technology: 3D printing, ink casting, micromachined lamination (3D PICLμM) for rapid prototyping of lab-on-a-chip (LOC) and biological devices. The technology uses cost-effective, makerspace-type microfabrication processes, all of which are ideally suited for low resource settings, and utilizing a combination of these processes, we have demonstrated the following devices: (i) 2D microelectrode array (MEA) targeted at in vitro neural and cardiac electrophysiology, (ii) microneedle array targeted at drug delivery through a transdermal route and (iii) multi-layer microfluidic chip targeted at multiplexed assays for in vitro applications. The 3D printing process has been optimized for printing angle, temperature of the curing process and solvent polishing to address various biofunctional considerations of the three demonstrated devices. We have depicted that the 3D PICLμM process has the capability to fabricate 30 μm sized MEAs (average 1 kHz impedance of 140 kΩ with a double layer capacitance of 3 μF), robust and reliable microneedles having 30 μm radius of curvature and ~40 N mechanical fracture strength and microfluidic devices having 150 μm wide channels and 400 μm fluidic vias capable of fluid mixing and transmitted light microparticle visualization. We believe our 3D PICLμM is ideally suited for applications in areas such as electrophysiology, drug delivery, disease in a dish, organ on a chip, environmental monitoring, agricultural therapeutic delivery and genomic testing.

Optimization of makerspace microfabrication techniques and materials for the realization of planar, 3D printed microelectrode arrays in under four days

“…Transitioning the fabrication of these devices from a cleanroom environment to a makerspace environment is an ideal solution for in vitro MEAs and it can result in rapid design to device, cost effectiveness, reduction of fabrication steps and disposability. [21][22][23][24] Since, these devices are mainly used for interfacing with cells, a resolution in the range of micrometers is needed, which is generally not achievable in a traditional makerspace environment. A "makerspace microfabrication" that enables a synergistic association of the various unit processes present in a makerspace combined with other traditional micromachining processes is needed for such MEAs along with the optimization of different materials.…”

“…The use of "makerspace microfabrication" for realization of biological microdevices has previously been reported by the authors in a novel process entitled "3D Printing, Ink Casting and Micromachined Lamination" or 3D PICLmM. 22 A stereolithography (SLA) apparatus is used to cure and build up a photopolymer resin to dene the framework of the devices. This resin is optically clear to allow for the transparency that makes glass MEA useful in optical assays.…”

“…19,26 With 3D PICLmM, a 3D printed MEA with an electrode density of 3 Â 3 was previously demonstrated as a proof of concept. 22 Optimizing the design, process and materials of this 3D PICLmM approach would allow for a desired end product of a transparent, high density, single well MEA that could be "used and tossed" during research. 15 Some issues with the previously reported 3D printed MEA include a low density array of electrodes, partially exposed silver ink which is cytotoxic, 27,28 uncontrolled electrode properties as the process involved electroless plating of platinum and manual assembly of the culture well.…”

“…15 Some issues with the previously reported 3D printed MEA include a low density array of electrodes, partially exposed silver ink which is cytotoxic, 27,28 uncontrolled electrode properties as the process involved electroless plating of platinum and manual assembly of the culture well. 22 A higher electrode density is desired in sensing applications because it allows for increased spatial and temporal resolution. Complete coverage of the silver electrodes with biocompatible metals would allow for better biocompatibility of the device.…”

Biocompatible 3D Printed Microneedles for Transdermal, Intradermal, and Percutaneous Applications

“…It has evolved via the introduction of different technologies such as stereolithography (SLA), fused deposition modeling (FDM), and two‐photon polymerization (TPP). SLA has been used in various works to produce MNs for transdermal drug delivery, mainly to fabricate plain/solid MNs . The delivery method can be either by coating the MNs with the required drug or can be preloaded in the case of biodegradable materials .…”