Shape displays which actively manipulate surface geometry are an expanding robotics domain with applications to haptics, manufacturing, aerodynamics, and more. However, existing displays often lack ...high-fidelity shape morphing, high-speed deformation, and embedded state sensing, limiting their potential uses. Here, we demonstrate a multifunctional soft shape display driven by a 10 × 10 array of scalable cellular units which combine high-speed electrohydraulic soft actuation, magnetic-based sensing, and control circuitry. We report high-performance reversible shape morphing up to 50 Hz, sensing of surface deformations with 0.1 mm sensitivity and external forces with 50 mN sensitivity in each cell, which we demonstrate across a multitude of applications including user interaction, image display, sensing of object mass, and dynamic manipulation of solids and liquids. This work showcases the rich multifunctionality and high-performance capabilities that arise from tightly-integrating large numbers of electrohydraulic actuators, soft sensors, and controllers at a previously undemonstrated scale in soft robotics.
•We present sub-kelvin thermal conductivity data for an artificial graphite, polyimides (3), titanium alloys (3), a shape memory alloy and a bulk metallic glass.•The heat flow along the length of a ...laminated flat cable can be predicted by composing the thermal conductivities of its constituent materials, but heat flow across its thickness cannot be predicted in this way.•Titanium alloys are useful as low thermal conductivity superconducting structural and flat cabling materials.•SCP-5050 VESPEL is a useful insulating structural material due to its very low thermal conductivity, and high strength and dimensional stability.•Structural parts made from bulk metallic glass would have thermal conductivity on par with stainless steel and could be manufactured via injection molding.
We present measurements of the low temperature thermal conductivity for materials useful in the construction of cryogenic supports for scientific instrumentation and in the fabrication of flat flexible cryogenic cabling. The materials we measure have relatively low thermal conductivity. We present a method for measuring the heat transfer coefficient of flat cabling and show, using an example, that the thermal conductivity of a flex cable is reasonably well predicted by composing the thermal conductivities of its constituent material layers. Room temperature physical and mechanical data is given for the materials studied, as well as an overview of relevant materials science and manufacturing details. Materials include Timet Ti 15-3 and Ti 21S, Materion alloy vit105 (LM105) in amorphous state, ATI Metals Nb-47Ti, Johnson Matthey nitinol (NiTi), Mersen graphite grade 2020, DuPont Pyralux coverlay and Vespel SCP-5050, and Fralock Cirlex polyimide sheets. All data is in the temperature range 0.05–2 K, and up to 5 K for SCP-5050.
We present measurements of the thermal conductivity between 0.05 and 1 K, and radioactive contamination levels, for some thermally isolating materials. TIMET Ti 15-3-3-3, Mersen grade 2020 graphite, ...Vespel SP-1, Vespel SP-22, Vespel SCP-5000, Vespel SCP-5050, Graphlite CFRP, and a Kapton/epoxy composite are all investigated. Thermal conductivities were measured using a single-heater longitudinal heat flow method. Material radioactivity was determined for the materials at a low background counting facility using a high-purity gamma detector and GEANT4 Monte Carlo simulations.
•Joint thermal conductance across bolted copper to copper connections has been tested from 60mK to 26K.•Surfaces passivated with citric acid were tested as an alternative to gold plating.•Results of ...joint thermal conductance testing are well fitted with a power law regression.•These results correlate well with data obtained from a literature survey.
Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60mK to 26K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.
Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS ...experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Finally, the results we obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.
We present measurements of the low temperature thermal conductivity for materials useful in the construction of cryogenic supports for scientific instrumentation and in the fabrication of flat ...flexible cryogenic cabling. The materials we measure have relatively low thermal conductivity. We present a method for measuring the heat transfer coefficient of flat cabling and show, using an example, that the thermal conductivity of a flex cable is reasonably well predicted by composing the thermal conductivities of its constituent material layers. Room temperature physical and mechanical data is given for the materials studied, as well as an overview of relevant materials science and manufacturing details. Materials include Timet Ti 15-3 and Ti 21S, Materion alloy vit105 (LM105) in amorphous state, ATI Metals Nb-47Ti, Johnson Matthey nitinol (NiTi), Mersen graphite grade 2020, DuPont Pyralux coverlay and Vespel SCP-5050, and Fralock Cirlex polyimide sheets. All data is in the temperature range 0.5 to 2 K, and up to 5 K for SCP-5050.
Vigilance, Workload, and Boredom: Two Competing Models Alikonis, Caroline R.; Warm, Joel S.; Matthews, Gerald ...
Proceedings of the Human Factors and Ergonomics Society Annual Meeting,
09/2002, Letnik:
46, Številka:
17
Journal Article
Recenzirano
Two models that seek to explain the high workload associated with vigilance tasks are the direct-cost and indirect-cost views. The former attributes the elevated workload to the high ...information-processing demand of the task; the latter attributes it to efforts to combat the boredom associated with monotonous vigilance tasks. A recent study by Hitchcock et al. (1999) provided support for the direct-cost view by showing that it is possible to lower the workload of vigilance through reductions in the information-processing load while leaving task-induced boredom unaffected. This study provides converging evidence for the direct-cost view: allowing observers to listen to a stress-reducing musical selection, Heart Zones, during a vigil lowered boredom while leaving the perceived workload of the task unaffected. The beneficial effect of the musical selection was limited to boredom; it had no impact upon post-vigil feelings of loss of task engagement and distress.
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