Ravichandran, Dharneedar

Abstract 3D printing, also known as additive manufacturing, holds immense potential for rapid prototyping and customized production of functional health‐related devices. With advancements in polymer chemistry and biomedical engineering, polymeric biomaterials have become integral to 3D‐printed biomedical applications. However, there still exists a bottleneck in the compatibility of polymeric biomaterials with different 3D printing methods, as well as intrinsic challenges such as limited printing resolution and rates. Therefore, this review aims to introduce the current state‐of‐the‐art in 3D‐printed functional polymeric health‐related devices. It begins with an overview of the landscape of 3D printing techniques, followed by an examination of commonly used polymeric biomaterials. Subsequently, examples of 3D‐printed biomedical devices are provided and classified into categories such as biosensors, bioactuators, soft robotics, energy storage systems, self‐powered devices, and data science in bioplotting. The emphasis is on exploring the current capabilities of 3D printing in manufacturing polymeric biomaterials into desired geometries that facilitate device functionality and studying the reasons for material choice. Finally, an outlook with challenges and possible improvements in the near future is presented, projecting the contribution of general 3D printing and polymeric biomaterials in the field of healthcare.

AbstractNanoparticles form long‐range micropatterns via self‐assembly or directed self‐assembly with superior mechanical, electrical, optical, magnetic, chemical, and other functional properties for broad applications, such as structural supports, thermal exchangers, optoelectronics, microelectronics, and robotics. The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. This article provides a comprehensive review of nanoparticle assembly formed primarily via the balance of forces at the nanoscale (e.g., van der Waals, colloidal, capillary, convection, and chemical forces) and nanoparticle‐template interactions (e.g., physical confinement, chemical functionalization, additive layer‐upon‐layer). The review commences with a general overview of nanoparticle self‐assembly, with the state‐of‐the‐art literature review and motivation. It subsequently reviews the recent progress in nanoparticle assembly without the presence of surface templates. Manufacturing techniques for surface template fabrication and their influence on nanoparticle assembly efficiency and effectiveness are then explored. The primary focus is the spatial organization and orientational preference of nanoparticles on non‐templated and pre‐templated surfaces in a controlled manner. Moreover, the article discusses broad applications of micropatterned surfaces, encompassing various fields. Finally, the review concludes with a summary of manufacturing methods, their limitations, and future trends in nanoparticle assembly.

AbstractPelvic organ prolapse (POP) is a dysfunction that affects a large proportion of women. Current support scaffolds’ lack of biocompatibility, biodegradability, and mechanical compliance are associated with surgical complications including erosion and pain, indicating the urgent need for new tissue scaffolds with customizable functions. A new material that uses polyvinyl alcohol (PVA) as the main ingredient and is chemically tuned to possess suitable mechanical properties and degradation rates for the surgical treatment of POP is developed. Specifically, the thiol‐norbornene “click” chemistry enables the sol‐gel transition of the biomaterial under UV‐light without side‐products. Meanwhile, NaOH treatment further toughens the hydrogel with a higher crosslink density. The PVA‐based biocompatible ink can be printed with UV‐facilitated direct ink writing due to the rapidly UV‐initiated chemical crosslink; in situ image analysis and machine learning methods are applied during this procedure to quantify and improve the printing quality. The cell viability results demonstrate the biocompatibility of the POP scaffolds, suggesting the potential for future animal studies and the possibility of clinical research. This study bridges polymer chemistry and manufacturing engineering with a specific tissue engineering application to solve the common disorder of POP, shedding light on individualized medicine and intelligent systems for biomedical engineering.

Abstract3D printing (additive manufacturing (AM)) has enormous potential for rapid tooling and mass production due to its design flexibility and significant reduction of the timeline from design to manufacturing. The current state‐of‐the‐art in 3D printing focuses on material manufacturability and engineering applications. However, there still exists the bottleneck of low printing resolution and processing rates, especially when nanomaterials need tailorable orders at different scales. An interesting phenomenon is the preferential alignment of nanoparticles that enhance material properties. Therefore, this review emphasizes the landscape of nanoparticle alignment in the context of 3D printing. Herein, a brief overview of 3D printing is provided, followed by a comprehensive summary of the 3D printing‐enabled nanoparticle alignment in well‐established and in‐house customized 3D printing mechanisms that can lead to selective deposition and preferential orientation of nanoparticles. Subsequently, it is listed that typical applications that utilized the properties of ordered nanoparticles (e.g., structural composites, heat conductors, chemo‐resistive sensors, engineered surfaces, tissue scaffolds, and actuators based on structural and functional property improvement). This review's emphasis is on the particle alignment methodology and the performance of composites incorporating aligned nanoparticles. In the end, significant limitations of current 3D printing techniques are identified together with future perspectives.