Characterization and Neutral Atom Beam Surface Modification of a Clear Castable Polyurethane for Biomicrofluidic Applications

Abstract

Polyurethanes (PU) are a broad class of polymers that offer good solvent compatibility and a wide range of properties that can be used to generate microfluidic layers. Here, we report the first characterization of a commercially available Shore 80D polyurethane (Ultraclear™ 480N) for biomicrofluidic applications. Studies included comparing optical clarity with Polydimethylsiloxane (PDMS) and using high-fidelity replica molding to produce solid PU structures from the millimeter to nanometer scales. Additionally, we report the first use of NanoAccel™ treatment in Accelerated Neutral Atom Beam (ANAB) mode to permanently roughen the surface of PU and improve the adhesion of breast cancer cells (MDA-MB-231) on PU. Surface energy measurements using Owens-Wendt equations indicate an increase in polar and total surface energy due to ANAB treatment. Fourier-transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) mode was used to demonstrate that the treatment does not introduce any new types of functional groups on the surface of Ultraclear™ PU. Finally, applicability in rapid prototyping for biomicrofluidics was demonstrated by utilizing a 3D-printing-based replica molding strategy to create PU microfluidic layers. These layers were sealed to polystyrene (PS) bases to produce PU-PS microfluidic chips. Ultraclear™ PU can serve as a clear and castable alternative to PDMS in biomicrofluidic studies.

Bimodal Nanocomposite Platform with Antibiofilm and Self-Powering Functionalities for Biomedical Applications

“…Measurement of Contact Angles and Surface Energy. Contact angles for 3 μL drops of Milli-Q water (MilliporeSigma), formamide (Sigma-Aldrich, St. Louis, MO), and diiodomethane (MilliporeSigma) were measured using the sessile drop method 35,36 on a contact angle goniometer (Ossila Ltd., Sheffield, U.K.). For BTO-nanocomposites, drops were allowed to stabilize on the surface for 90 s before measurement.…”

“…Three independent runs were conducted with 10 drops per sample. Surface energy values for BTO-nanocomposites and lawns of S. mutans were estimated by the Owens−Wendt method 35,39 using three test liquidswater, formamide, and diiodomethane. Surface free energy parameters 40 (Table S1) and average contact angles were used to calculate polar and dispersive surface energies from eq S1.…”

A Review of Methods to Modify the PDMS Surface Wettability and Their Applications

“…The silicone elastomer known as polydimethylsiloxane (PDMS) has been widely employed as the main substrate in various micro/nano applications. These include microcontact printing [ 1 ], microfluidics [ 2 , 3 , 4 , 5 ], and microreactors [ 6 ], as well as in fabric coatings and water–oil separation [ 7 , 8 , 9 , 10 , 11 , 12 ], among many other applications. This is due to its attractive characteristics, such as easiness of manufacturing, non-toxicity, optical transparency, low cost, favourable biocompatibility, elastic nature, ease to process and advantageous chemical and physical properties, the malleability for moulding on (sub)micrometric scales, and effective adhesion to itself and to the glass [ 13 , 14 , 15 , 16 , 17 ].…”

A 3D‐Printed Customizable Platform for Multiplex Dynamic Biofilm Studies

“…[ 1 ] Over the past few decades, 3D printing (3DP) has fundamentally revolutionized the materials, processes, and skills required to generate geometrically complex objects in a timely and cost‐effective manner. [ 2 ] For example, the advancement of 3DP techniques has enabled inexpensive and facile prototyping of microfluidic molds [ 3 ] and microfluidic channels with adequate rigidity and reusability. [ 4 ] With the development and widespread use of Computer Aided Design software to create 3D objects, the barrier to entry for new users to create and modify designs has been lowered.…”