Additive Manufacturing of Magnetic Soft Materials and Magnetic Origami Robot

The soft actuator has been using in many applications such as robotics, biochemical devices, and consumer products. Magnetic Soft Materials (MSMs) are one of the soft actuators that have functions of reversible shape transformation, untethered, fast, and shape controllable under applied magnetic fields. Magnetic shape memory polymers(M-SMPs), as one of the MSMs, have a new type of function: shape locking. With temperature changing, it can increase or decrease its Young's Modules to change its stiffness which both achieved shape-changing and energy saving. However, its thermal curing fabrication method limits its design shape only to simple geometry shapes. Here, with our photo-curing method and developed multimaterial printing technology, we have designed complex structures contain both M-SMPs and MSMs. Under thermal and magnetic actuation, the complex structures are capable of shape-changing and shape locking. It accomplished multiple usages relative to different shapes in one construction. To increases the functionality of our designs, we further analyze one of the unique patterns of origami, a paper-folding art, called Kresling origami. Kresling origami contains a propeller-like structure with two stable states: deployed state and folded state. With a magnetic-responsive plate on the side of the structure, our Kresling origami robot performs a swimming motion under a rotating magnetic field. In this article, both magnetic soft material and magnetic origami robot are separately analyzed, and we believe a combination with both technologies has great potentials in biomedical applications.No embargoAcademic Major: Mechanical Engineerin

Multiple equilibrium states of a curved-sided hexagram:Part I-Stability of states

The stability of the multiple equilibrium states of a hexagram ring with six curved sides is investigated. Each of the six segments is a rod having the same length and uniform natural curvature. These rods are bent uniformly in the plane of the hexagram into equal arcs of 120deg or 240deg and joined at a cusp where their ends meet to form a 1-loop planar ring. The 1-loop rings formed from 120deg or 240deg arcs are inversions of one another and they, in turn, can be folded into a 3-loop straight line configuration or a 3-loop ring with each loop in an "8" shape. Each of these four equilibrium states has a uniform bending moment. Two additional intriguing planar shapes, 6-circle hexagrams, with equilibrium states that are also uniform bending, are identified and analyzed for stability. Stability is lost when the natural curvature falls outside the upper and lower limits in the form of a bifurcation mode involving coupled out-of-plane deflection and torsion of the rod segments. Conditions for stability, or lack thereof, depend on the geometry of the rod cross-section as well as its natural curvature. Rods with circular and rectangular cross-sections will be analyzed using a specialized form of Kirchhoff rod theory, and properties will be detailed such that all four of the states of interest are mutually stable. Experimental demonstrations of the various states and their stability are presented. Part II presents numerical simulations of transitions between states using both rod theory and a three-dimensional finite element formulation, includes confirmation of the stability limits established in Part I, and presents additional experimental demonstrations and verifications

Multiple equilibrium states of a curved-sided hexagram: Part II-Transitions between states

Curved-sided hexagrams with multiple equilibrium states have great potential in engineering applications such as foldable architectures, deployable aerospace structures, and shape-morphing soft robots. In Part I, the classical stability criterion based on energy variation was used to study the elastic stability of the curved-sided hexagram and identify the natural curvature range for stability of each state for circular and rectangular rod cross-sections. Here, we combine a multi-segment Kirchhoff rod model, finite element simulations, and experiments to investigate the transitions between four basic equilibrium states of the curved-sided hexagram. The four equilibrium states, namely the star hexagram, the daisy hexagram, the 3-loop line, and the 3-loop "8", carry uniform bending moments in their initial states, and the magnitudes of these moments depend on the natural curvatures and their initial curvatures. Transitions between these equilibrium states are triggered by applying bending loads at their corners or edges. It is found that transitions between the stable equilibrium states of the curved-sided hexagram are influenced by both the natural curvature and the loading position. Within a specific natural curvature range, the star hexagram, the daisy hexagram, and the 3-loop "8" can transform among one another by bending at different positions. Based on these findings, we identify the natural curvature range and loading conditions to achieve transition among these three equilibrium states plus a folded 3-loop line state for one specific ring having a rectangular cross-section. The results obtained in this part also validate the elastic stability range of the four equilibrium states of the curved-sided hexagram in Part I. We envision that the present work could provide a new perspective for the design of multi-functional deployable and foldable structures

Patient-centric health-care data processing using streams and asynchronous technology

This paper describes a system in detail, which takes in depersonalized data collected by a patient medication management system, carries out reformatting and basic calculations on the data, then stores the resulting information into a database for retrieval, visualization, and further analysis. An investigation is also carried out to create a new way of developing a data analysis application that is efficient and simple to create/code, while avoiding the use of overly complicated libraries to boost performance or investing in expensive hardware. A description of the technologies, algorithms, software tools, and software development process shall be provided. The results from the creation of this application will also be covered while indicating relevant uses for the application, pitfalls/ challenges, and future improvements that can be carried out to enhance and improve the system. This application makes use of data collected by an existing patient prescription tracking app that was built by a third-party company that provided dummy data that were used as a guide to develop the system. The application/system created consists of four main sections, a data model project that was used to create the database schema, a "cruncher" project that consists of scripts used to extract data from the existing database, then transforms it into the needed information to be stored, an application programming interface (API) that is used to easily query/retrieve information from the database, and lastly a set of interfaces that visualized the data stored once collected by the cruncher project for easy interpretation and investigation. Disclaimers: The system described in this paper was developed and tested locally and not in any production environment. All data used for the creation of this paper are dummy data and not real user data. Therefore, all results are simulated and, in no way, violate any real user's privacy. All functionality proposed and developed in this solution represent the potential applications of an analytics tool of this nature and do not represent how any collaborator in this project currently uses the developed system in any real-world/production environment.</p

The Nitrogen-Removal Efficiency of a Novel High-Efficiency Salt-Tolerant Aerobic Denitrifier, Halomonas Alkaliphile HRL-9, Isolated from a Seawater Biofilter

Aerobic denitrification microbes have great potential to solve the problem of NO3&minus;-N accumulation in industrialized recirculating aquaculture systems (RASs). A novel salt-tolerant aerobic denitrifier was isolated from a marine recirculating aquaculture system (RAS) and identified as Halomonas alkaliphile HRL-9. Its aerobic denitrification performance in different dissolved oxygen concentrations, temperatures, and C/N ratios was studied. Investigations into nitrogen balance and nitrate reductase genes (napA and narG) were also carried out. The results showed that the optimal conditions for nitrate removal were temperature of 30 &deg;C, a shaking speed of 150 rpm, and a C/N ratio of 10. For nitrate nitrogen (NO3&minus;-N) (initial concentration 101.8 mg&middot;L&minus;1), the sole nitrogen source of the growth of HRL-9, the maximum NO3&minus;-N removal efficiency reached 98.0% after 24 h and the maximum total nitrogen removal efficiency was 77.3% after 48 h. Nitrogen balance analysis showed that 21.7% of NO3&minus;-N was converted into intracellular nitrogen, 3.3% of NO3&minus;-N was converted into other nitrification products (i.e., nitrous nitrogen, ammonium nitrogen, and organic nitrogen), and 74.5% of NO3&minus;-N might be converted to gaseous products. The identification of functional genes confirmed the existence of the napA gene in strain HRL-9, but no narG gene was found. These results confirm that the aerobic denitrification strain, Halomonas alkaliphile HRL-9, which has excellent aerobic denitrification abilities, can also help us understand the microbiological mechanism and transformation pathway of aerobic denitrification in RASs