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Kumar G.,Yale University | Desai A.,Tanner Research, Inc. | Schroers J.,Yale University
Advanced Materials | Year: 2011

Bulk metallic glasses (BMGs) are strong, highly elastic, and resistant to wear but still find limited utility due to their macroscopic brittle nature, high costs, and difficulty of processing, particularly when complex shapes are desired. These drawbacks can be mitigated when BMGs are used in miniature parts (< 1 cm), an application which takes advantage of BMGs' enhanced plasticity at small length scales as well the insignificant material cost associated with such parts. As an alternative to traditional metal processing techniques, thermoplastic forming (TPF)-based microfabrication methods have been developed which can process some BMGs like plastics. In this article, we discuss the properties and fabrication of BMGs on minuscule length scales to explore their prospective application in small-scale devices. Limitations of bulk metallic glasses (BMGs) imposed by their brittle behavior and high costs are overcome by fabricating BMG parts on miniature length scales, which take advantage of their enhanced plasticity and reduced costs. This opens up new opportunities for BMGs in the fields of MEMS, bio-implants, miniature tools, self-assembly templates, nanoimprinting, and the study of size-effects. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Shoemaker P.A.,Tanner Research, Inc.
Neurocomputing | Year: 2011

The macroscopic current/voltage relationship of NMDA receptor ion channels is nonmonotonic under physiological conditions, which can give rise to bistable and amplifying/facilitatory behavior in neurons and neural structures, supporting significant computational primitives. Conditions under which bistable regimes of operation prevail, and also general amplifying properties associated with active NMDA receptors, are examined in a single compartment enclosed by a cell membrane, and subsequently in cable-like dendrites under varying boundary conditions. Methodology consists of numerical and mathematical analyses of stationary versions of equations governing the electrical behavior of these systems. Bistability mediated by NMDA receptors requires interaction with other conductances in the membrane or cytoplasm, with particular importance attached to membrane potassium conductance, especially that of inward-rectifying potassium channels. A corollary conclusion is that coactivation of GABAB synaptic receptors or SK channels is a computationally powerful and sometimes necessary adjunct condition for NMDA receptor-mediated bistability. Neural multistability due to dendritic bistability is considered, including the case of closely coupled dendrites. The characteristics of coactivation-dependent facilitation, and amplifying states in which NMDA receptor activation boosts the efficacy of other classes of synapses, are also described. Coactive inward-rectifying potassium channels are found to significantly affect the characteristics of such amplification. © 2011 Elsevier B.V. Source

Aptekar J.W.,Howard Hughes Medical Institute | Shoemaker P.A.,Tanner Research, Inc. | Frye M.A.,Howard Hughes Medical Institute
Current Biology | Year: 2012

Visual figures may be distinguished based on elementary motion or higher-order non-Fourier features, and flies track both [1]. The canonical elementary motion detector, a compact computation for Fourier motion direction and amplitude, can also encode higher-order signals provided elaborate preprocessing [2-4]. However, the way in which a fly tracks a moving figure containing both elementary and higher-order signals has not been investigated. Using a novel white noise approach, we demonstrate that (1) the composite response to an object containing both elementary motion (EM) and uncorrelated higher-order figure motion (FM) reflects the linear superposition of each component; (2) the EM-driven component is velocity-dependent, whereas the FM component is driven by retinal position; (3) retinotopic variation in EM and FM responses are different from one another; (4) the FM subsystem superimposes saccadic turns upon smooth pursuit; and (5) the two systems in combination are necessary and sufficient to predict the full range of figure tracking behaviors, including those that generate no EM cues at all [1]. This analysis requires an extension of the model that fly motion vision is based on simple elementary motion detectors [5] and provides a novel method to characterize the subsystems responsible for the pursuit of visual figures. © 2012 Elsevier Ltd. Source

Agency: Department of Defense | Branch: Missile Defense Agency | Program: SBIR | Phase: Phase I | Award Amount: 99.99K | Year: 2015

Current methods for measuring optical figure and transmitted wavefront error are challenged for large aspheric optical components . Lack of symmetry and large size make traditional measurement techniques impractical. Tanner Research proposes to develop an approach that overcomes these obstacles by leveraging existing techniques with advanced algorithms and a customized mechanism that enables a practical means for measuring surface finish and wavefront distortion. The goal is a compact, low-cost metrology instrument that produces surface finish and wavefront error maps, which can be used in the iterative refinement of large aspheric objects. (Approved for Public Release 15-MDA-8482 (17 November 15))

Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 80.00K | Year: 2014

Thermally Initiated Venting Systems (TIVS) are a safety prerequisite for meeting DOD IM requirements. Tanner Research will leverage existing TRL-7 electronic Safe and Arm and Arm/Fire device (ESAD/EAFD) hardware in combination with COTS energy harvesting to develop and demonstrate in Phase I a proof of concept in-line electronic TIVS. To preclude Fast- and Slow Cook-Off (FCO/SCO) incidents and catastrophic losses will require multiple sensor integration and embedded electronic architecture. That is,"smart-munitions-related"sensor-fuzed architectures which are compact, require, almost no stored energy, and also are able to be customized for a variety of environments. . Tanner Research proposes to implement such an electronic TIVS meeting MIL-STD-2105 criteria for venting utilizing IM-compliant ESAD/EAFD and shaped-charge EFI detonator(s) or linear arrays that are powered and controlled by energy scavenging. Operating principles include: event detection, weakening of motor casing with focused blast-energy, or use one or more linear cutting charges in the event of slow temperature rise meeting SCO criteria, or rapid, widespread FCO conditions (e.g., fire).

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