The research directions of Prof. Ryan D. Sochol’s Bioinspired Advanced Manufacturing (BAM) Laboratory all stem from the use of additive manufacturing or “3D printing” to advance biomedical fields.  Prior to becoming an Assistant Professor, a large portion of Dr. Sochol’s research centered on taking advantage of the scaling-induced benefits of micro/nanotechnologies for applications such as point-of-care medical diagnostics.  These efforts, however, also revealed the critical limitations of traditional micro/nanoscale manufacturing techniques, not only in terms of the time-, cost-, and labor-intensive protocols, but also the inherent geometric (“2.5D”) constraints.  Thus, the BAM Lab focuses on pioneering alternative micro/nanofabrication strategies based instead on state-of-the-art additive manufacturing technologies, with a focus on applications that objectively demand its use—i.e., cases requiring device architectures and/or functionalities that would be difficult or infeasible to achieve via conventional manufacturing methods.

“Direct Laser Writing (DLW)” is a two-photon (or multi-photon) polymerization technique that entails rapidly scanning a tightly focused laser to crosslink (i.e., solidify) a photoreactive material at designed locations to ultimately produce 3D objects with feature resolutions down to the 100 nanometer range.  The key challenge in employing DLW for microfluidic applications is that the high resolution has rendered it poorly suited for printing the macro-to-micro fluidic interfaces—e.g., the inlet and outlet ports required for delivering/retrieving fluids.  To overcome this barrier, our group has invented “in situ DLW (isDLW)” and “ex situ DLW (esDLW)” strategies for printing 3D microfluidic technologies with micron-to-submicron-scale feature resolution. 

Over the past decade, “soft robots”—systems composed of compliant materials that are typically actuated via fluidic means (e.g., hydraulics and/or pneumatics)—have garnered significant interest as the inherent adaptability and safety for human-robot interactions has opened the door to new forms of rehabilitation and medical devices (e.g., soft robotic sleeves for pumping ailing hearts).  Yet this emergence of the soft robotics field has also presented new challenges associated with controlling the underlying fluidics of such systems—challenges our group has worked to address by means of additive manufacturing.

“PolyJet 3D Printing” is an inkjet-based process by which multiple photoreactive materials (and a sacrificial support material) are dispensed in parallel to produce multi-material 3D objects in a line-by-line, layer-by-layer manner.  We introduced a strategy for additively manufacturing fully assembled soft robots—including all of the soft actuators, integrated fluidic circuitry, and body features—autonomously in a single step via PolyJet 3D printing.  Not only is the paper “open access”, but all of the electronic design files are available through GitHub so that anyone can readily download, modify on demand, and/or reproduce (i.e., 3D print on site or via a commercial service) these capabilities.  We have also employed our isDLW and esDLW approaches for manufacturing microfluidic circuitry and integrating these components with soft microrobotic actuators with a focus on medical/surgical robotics applications.

The ability to manufacture geometrically complex, yet functionally advantageous microsystems comprising multiple fully integrated materials—e.g., corresponding to distinct optical, biological, chemical, electrical, and/or mechanical properties—holds promise for catalyzing new technologies in optics, photonics, biomedical, and microelectronics fields.  Historically, however, DLW-printed microsystems have near-universally included only one material due to the limits of conventional multi-material DLW protocols.  To address this barrier, we introduced “microfluidic multi-material DLW” .