Educational Soft Underwater Robot with an Electromagnetic Actuation.

As demonstrated by the Soft Robotics Toolkit Platform, compliant robotics pose an exciting educational opportunity. Underwater robotics using soft undulating fins is an expansive research topic with applications such as exploration of underwater life or replicating 3d swarm behavior. To make this research area accessible for education we developed Educational Soft Underwater Robot with Electromagnetic Actuation (ESURMA), a humanoid soft underwater robot. We achieved advances in simplicity, modularity, and performance by implementing electromagnetic actuation into the caudal fin. An electromagnet, including electronics, is placed in a waterproof housing, and permanent magnets are embedded in a soft silicone cast tail. The force from their magnetic interaction results in a bending movement of the tail. The magnetic actuation is simple to implement and requires no mechanical connection between the actuated component and the electrically controlled coil. This enables robust waterproofing and makes the device fully modular. Thanks to the direct and immediate transmission of force, experimental flapping frequencies of 14 Hz were achieved, an order of magnitude higher compared to pneumatically actuated tails. The completely silent actuation of the caudal fin enables a maximum swimming speed of 14.3 cm/s. With its humanoid shape, modular composition, and cost efficiency ESURMA represents an attractive platform for education and demonstrates an alternative method of actuating soft structures.

Development and Implementation of a Biometrics Device Design Project in an Introductory BME Course to Support Student Wellness.

Mental health challenges have been rising across college campuses. To destigmatize wellness practices and promote student mental health, we present a novel technical project in an introductory bioengineering course that explores stress management techniques through physiology, biosensors, and design. We hypothesize that if students measure objective, physiologic impacts of stress management techniques on themselves, they may be more likely to realize the benefits and use those techniques when needed. Additionally, through this data-driven project, we aim to appeal to engineers' critical thinking nature. To support students in selecting stress management techniques for themselves, mindfulness is introduced and practiced in the course. Initial student feedback on the introduction of mindfulness into the classroom is positive. The COVID-19 pandemic has emphasized the need to focus on student wellbeing in addition to physical health. Integration of wellness into the core curriculum can normalize the use of these resources within engineering departments and colleges and equip students with stress management tools for their careers. Ultimately, this curricular development lays the groundwork for institutional enhancement of undergraduate STEM education by supporting student wellness through the engineering curriculum. Supplementary Information: The online version contains supplementary material available at 10.1007/s43683-021-00060-1.

Soluble Polymer Pneumatic Networks and a Single-Pour System for Improved Accessibility and Durability of Soft Robotic Actuators.

Soft robotic devices can be used to demonstrate mechanics, robotics, and health care devices in classrooms. The complexity of soft robotic actuator fabrication has limited its classroom use. We propose a single-mold method of fabricating soluble insert actuators (SIAs) to simplify existing actuator fabrication methods using common accessible materials. This was accomplished by embedding molded soluble structures into curing polymer with custom molds and later dissolving the internal structure, leaving behind a hollow pneumatic network. Compared with similar actuators, SIAs actuated with comparable deformations while withstanding higher pressures for longer durations. SIAs have simple and accessible fabrication, resulting in durable actuators. We propose this method of actuator fabrication for use in K-12 schools to engage young students in this emerging field. In addition to silicone actuators, we show application of SIAs in biodegradable actuator fabrication, in a simplified model for classroom demonstration, and use in a glove designed to teach students the tactile art of ceramics.

The Role of Soft Robotic Micromachines in the Future of Medical Devices and Personalized Medicine.

Developments in medical device design result in advances in wearable technologies, minimally invasive surgical techniques, and patient-specific approaches to medicine. In this review, we analyze the trajectory of biomedical and engineering approaches to soft robotics for healthcare applications. We review current literature across spatial scales and biocompatibility, focusing on engineering done at the biotic-abiotic interface. From traditional techniques for robot design to advances in tunable material chemistry, we look broadly at the field for opportunities to advance healthcare solutions in the future. We present an extracellular matrix-based robotic actuator and propose how biomaterials and proteins may influence the future of medical device design.

Production-scale fibronectin nanofibers promote wound closure and tissue repair in a dermal mouse model.

Wounds in the fetus can heal without scarring. Consequently, biomaterials that attempt to recapitulate the biophysical and biochemical properties of fetal skin have emerged as promising pro-regenerative strategies. The extracellular matrix (ECM) protein fibronectin (Fn) in particular is believed to play a crucial role in directing this regenerative phenotype. Accordingly, Fn has been implicated in numerous wound healing studies, yet remains untested in its fibrillar conformation as found in fetal skin. Here, we show that high extensional (∼1.2 ×105 s-1) and shear (∼3 ×105 s-1) strain rates in rotary jet spinning (RJS) can drive high throughput Fn fibrillogenesis (∼10 mL/min), thus producing nanofiber scaffolds that are used to effectively enhance wound healing. When tested on a full-thickness wound mouse model, Fn nanofiber dressings not only accelerated wound closure, but also significantly improved tissue restoration, recovering dermal and epidermal structures as well as skin appendages and adipose tissue. Together, these results suggest that bioprotein nanofiber fabrication via RJS could set a new paradigm for enhancing wound healing and may thus find use in a variety of regenerative medicine applications.

Engineering hybrid polymer-protein super-aligned nanofibers via rotary jet spinning.

Cellular microenvironments are important in coaxing cells to behave collectively as functional, structured tissues. Important cues in this microenvironment are the chemical, mechanical and spatial arrangement of the supporting matrix in the extracellular space. In engineered tissues, synthetic scaffolding provides many of these microenvironmental cues. Key requirements are that synthetic scaffolds should recapitulate the native three-dimensional (3D) hierarchical fibrillar structure, possess biomimetic surface properties and demonstrate mechanical integrity, and in some tissues, anisotropy. Electrospinning is a popular technique used to fabricate anisotropic nanofiber scaffolds. However, it suffers from relatively low production rates and poor control of fiber alignment without substantial modifications to the fiber collector mechanism. Additionally, many biomaterials are not amenable for fabrication via high-voltage electrospinning methods. Hence, we reasoned that we could utilize rotary jet spinning (RJS) to fabricate highly aligned hybrid protein-polymer with tunable chemical and physical properties. In this study, we engineered highly aligned nanofiber constructs with robust fiber alignment from blends of the proteins collagen and gelatin, and the polymer poly-ε-caprolactone via RJS and electrospinning. RJS-spun fibers retain greater protein content on the surface and are also fabricated at a higher production rate compared to those fabricated via electrospinning. We measured increased fiber diameter and viscosity, and decreasing fiber alignment as protein content increased in RJS hybrid fibers. RJS nanofiber constructs also demonstrate highly anisotropic mechanical properties mimicking several biological tissue types. We demonstrate the bio-functionality of RJS scaffold fibers by testing their ability to support cell growth and maturation with a variety of cell types. Our highly anisotropic RJS fibers are therefore able to support cellular alignment, maturation and self-organization. The hybrid nanofiber constructs fabricated by RJS therefore have the potential to be used as scaffold material for a wide variety of biological tissues and organs, as an alternative to electrospinning.