Extrusion-based additive manufacturing (EBAM) or 3D printing is used to produce customized prototyped parts. The majority of the polymers used with EBAM show moisture sensitivity. However, moisture effects become more pronounced in polymers used for critical applications, such as biomedical stents, sensors, and actuators. The effects of moisture on the manufacturing process and the long-term performance of Shape Memory Polyurethane (SMPU) have not been fully investigated in the literature. This study focuses primarily on block-copolymer SMPUs that have two different hard/soft (h/s) segment ratios. It investigates the effect of moisture on the various properties via studying: (i) the effect of moisture trapping within these polymers and the consequences when manufacturing; (ii) and the effect on end product performance of plasticization by moisture. Results indicate that higher h/s SMPU shows higher microphase separation, which leads to an increase of moisture trapping within the polymer. Understanding moisture trapping is critical for EBAM parts due to an increase in void content and a decrease in printing quality. The results also indicate a stronger plasticizing effect on polymers with lower h/s ratio but with a more forgiving printing behavior compared to the higher h/s ratio.

Shape memory materials are an innovative type of materials that reversibly store a temporary shape and recover back to the original dimensions with the application of an external mechanism such as heat. Shape memory polymers (SMP), specifically thermoplastic SMP (e.g. shape memory polyurethane (SMPU)) have received much attention during the past decade because of the promising future applications and advantages such as ease of processability for thermoplastic SMP (e.g. by 3-D printing), cost, and biocompatibility. In the biomedical field, applications such as stents, surgical sutures, and orthodontic devices, amongst others have been proposed. The addition of fillers to the material can modify the material to improve their load bearing capabilities. Bio-based fillers such as cellulose nanocrystals (CNC) have been proposed in a variety of reinforcing applications. The present work focuses on the experimental description of the addition of nonmodified CNC to SMPU. The work studied the effect on melt-extruded ribbons, for 0, 0.5, 1, 2, and 4 wt%. An increase of yield point, toughness, flexural modulus, recovery rate, and decrease of total time showed that SMPU/CNC nanocomposites are a potential candidate to use in future biomedical applications.

BACKGROUND: Recent advancements in digital workflows, including the use of 3D printing, are transforming the prosthetics and orthotics (P&O) field. Digital technologies offer opportunities to deliver P&O services that are more efficient by reducing design and fabrication times, are less wasteful through the elimination or reduction of consumables, including plaster, foam and other materials, and are more repeatable by having digitally saved designs. Despite known advantages, the adoption of digital workflows in P&O has been inconsistent, underscoring the need for cross-sector collaboration to guide the field using evidence-informed approaches. OBJECTIVE: To collaborate with key interest groups to identify priority areas for advancing the adoption and implementation of digital workflows in the P&O field. METHODOLOGY: A modified Delphi approach was used to inform the structure of a Canada-wide initiative and involved participation of 79 representatives from key interest groups, including prosthetists, orthotists, technicians, biomedical engineers, researchers, and people with limb absence/difference. Research priorities were identified through online surveys followed by a hybrid meeting during which attendees engaged in small- and large-group discussions to refine and select priorities. RESULTS: Five key digital P&O research priorities were identified: (1) strengthening evidence on device quality and system performance compared to traditional methods; (2) developing economic and reimbursement models to support clinical integration; (3) improving education and training for digital workflows; (4) establishing standardized practice guidelines; and (5) increasing key interest group engagement to better understand user needs and perspectives. While the general components of digital workflows are now broadly understood, future efforts should focus on more specific contexts, and discussions should be more targeted and disaggregated (e.g., by device type, patient population, or care setting) and include experts with context-specific experience. CONCLUSION: This collaboration initiative provides a strategic roadmap for advancing the adoption of digital workflows in the P&O field and supports the development of national collaborations aimed at fostering innovations and evidence-based practice. Layman's Abstract Recent advances in digital technologies, including three-dimensional (3D) printing, are changing how prostheses and orthoses are designed and fabricated. Digital workflows are the processes of using digital technologies to design and create prostheses or orthoses. These approaches may improve prostheses and orthoses care by reducing design and fabrication time, decreasing waste by reducing the use of plaster and other materials, and improving consistency by allowing designs to be digitally stored and reused. Despite these potential benefits, digital workflows are not yet widely used in clinical practice. Barriers such as limited evidence, gaps in education and training, cost and reimbursement challenges, and a lack of shared standards have slowed adoption. To help address these challenges, a Canada-wide initiative was conducted to bring together key interest groups and develop a shared research agenda. Using a structured consensus-building approach, 79 invitees (including prosthetists, orthotists, biomedical engineers, researchers, and people who use prostheses and/or orthoses) contributed through online surveys and a hybrid meeting that included group discussions. Five main research priorities were identified: generating stronger evidence comparing digitally produced prostheses or orthoses with traditionally made devices, improving education and training for digital workflows, developing economic and reimbursement models that support routine clinical use, creating baseline guidelines to promote consistent and safe practices, and increasing engagement with key interest groups to better understand their perspectives and needs. Overall, this work provides a roadmap to guide future initiatives and collaboration, supporting innovation and evidence-informed use of digital workflows in prostheses and orthoses care. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/46848/35280 How To Cite: Andrysek J, Mayo A.L, Ngan C.C, Blocka D, Pendse V, Calovini E, et al. Developing a research agenda in digital workflows for the fabrication of prostheses and orthoses. Can Prosthet Orthot J. 2026;9(2):4. https://doi.org/10.33137/cpoj.v9i2.46848 Corresponding Author: Prof. Jan Andrysek, PhDAffiliation: 1) Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada; 2) Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.E-Mail: JAndrysek@hollandbloorview.caORCID ID: https://orcid.org/0000-0002-4976-1228