Dual integrated actuators for extended range high speed atomic force microscopy

Cataloged from PDF version of article.A flexible system for increasing the throughput of the atomic force microscope without sacrificing imaging range is presented. The system is based on a nested feedback loop which controls a micromachined cantilever that contains both an integrated piezoelectric actuator and an integrated thermal actuator. This combination enables high speed imaging (2 mm/s) over an extended range by utilizing the piezoelectric actuator’s high bandwidth (15 kHz) and thermal actuator’s large response (300 nm/V). A constant force image, where the sample topography exceeds the range of the piezoelectric actuator alone, is presented. It has also been demonstrated that the deflection response of the thermal actuator can be linearized and controlled with an integrated diode. © 1999 American Institute of Physic

High-speed tapping mode imaging with active Q control for atomic force microscopy

Cataloged from PDF version of article.The speed of tapping mode imaging with the atomic force microscope(AFM) has been increased by over an order of magnitude. The enhanced operation is achieved by (1) increasing the instrument’s mechanical bandwidth and (2) actively controlling the cantilever’s dynamics. The instrument’s mechanical bandwidth is increased by an order of magnitude by replacing the piezotube z-axis actuator with an integrated zinc oxide (ZnO)piezoelectric cantilever. The cantilever’s dynamics are optimized for high-speed operation by actively damping the quality factor (Q) of the cantilever. Active damping allows the amplitude of the oscillating cantilever to respond to topography changes more quickly. With these two advancements, 80μm×80 μm high-speed tapping mode images have been obtained with a scan frequency of 15 Hz. This corresponds to a tip velocity of 2.4 mm/s. © 2000 American Institute of Physic

LiftUpp: Support to Develop Learner Performance

Various motivations exist to move away from the simple assessment of knowledge towards the more complex assessment and development of competence. However, to accommodate such a change, high demands are put on the supporting e-infrastructure in terms of intelligently collecting and analysing data. In this paper, we discuss these challenges and how they are being addressed by LiftUpp, a system that is now used in 70% of UK dental schools, and is finding wider applications in physiotherapy, medicine and veterinary science. We describe how data is collected for workplace-based development in dentistry using a dedicated iPad app, which enables an integrated approach to linking and assessing work flows, skills and learning outcomes. Furthermore, we detail how the various forms of collected data can be fused, visualized and integrated with conventional forms of assessment. This enables curriculum integration, improved real-time student feedback, support for administration, and informed instructional planning. Together these facets contribute to better support for the development of learners' competence in situated learning setting, as well as an improved experience. Finally, we discuss several directions for future research on intelligent teaching systems that are afforded by using the design present within LiftUpp.Comment: Short 4-page version to appear at AIED 201

Immersive full-surround multi-user system design

This paper describes our research in full-surround, multimodal, multi-user, immersive instrument design in a large VR instrument. The three-story instrument, designed for large-scale, multimodal representation of complex and potentially high-dimensional information, specifically focuses on multi-user participation by facilitating interdisciplinary teams of co-located researchers in exploring complex information through interactive visual and aural displays in a full-surround, immersive environment. We recently achieved several milestones in the instrument's design that improves multi-user participation when exploring complex data representations and scientific simulations. These milestones include affordances for "ensemble-style" interaction allowing groups of participants to see, hear, and explore data as a team using our multi-user tracking and interaction systems; separate visual display modes for rectangular legacy content and for seamless surround-view stereoscopic projection using 4 high-resolution, high-lumen projectors with hardware warping and blending integrated with 22 small-footprint projectors placed above and below the instrument's walkway; and a 3D spatial audio system enabling a variety of sound spatialization techniques. These facilities can be accessed and controlled by a multimodal framework for authoring applications integrating visual, audio, and interactive elements. We report on the achieved instrument design. © 2014 Elsevier Ltd. All rights reserved