Ion camera development for real–time acquisition of localised pH responses using the CMOS based 64×64–pixel ISFET sensor array technology

This thesis presents the development and test of an integrated ion camera chip for monitoring highly localised ion fluxes of electrochemical processes using an ion sensitive sensor array. Ionic concentration fluctuations are shown to travel across the sensor array as a result of citric acid injection and the BZ-reaction. The imaging capability of non-equilibrium chemical activities is also demonstrated monitoring self-assembling micrometre sized polyoxometalate tubular and membranous architectures. The sufficient spatial resolution for the visualisation of the 10-60 µm wide growing trajectories is provided by the dense sensor array containing 64×64 pixels. In the case of citric acid injection and the BZ-reaction the ion camera chip is shown to be able to resolve pH differences with resolution as low as the area of one pixel. As a result of the transient and volatile ionic fluxes high time resolution is required, thus the signal capturing can be performed in real.time at the maximum sampling rate of 40 µs per pixel, 10.2 ms per array. The extracted sensor data are reconstructed into ionic images and thus the ionic activities can be displayed as individual figures as well as continuous video recordings. This chip is the first prototype in the envisioned establishment of a fully automated CMOS based ion camera system which would be able to image the invisible activity of ions using a single microchip. In addition the capability of detecting ultra-low level pH oscillations in the extracellular space is demonstrated using cells of the slime mould organism. The detected pH oscillations with extent of ~0.022 pH furthermore raise the potential for observing fluctuations of ion currents in cell based tissue environments. The intrinsic noise of the sensor devices are measured to observe noise effect on the detected low level signals. It is experimentally shown that the used ion sensitive circuits, similarly to CMOS, also demonstrate 1/f noise. In addition the reference bias and pH sensitivity of the measured noise is confirmed. Corresponding to the measurement results the noise contribution is approximated with a 28.2 µV peak-to-peak level and related to the 450 µV �+/- 70 µV peak-to-peak oscillations amplitudes of the slime mould. Thus a maximum intrinsic noise contribution of 6.2 �+/- 1.2 % is calculated. A H+ flickering hypothesis is also presented that correlates the pH fluctuations on the surface of the device with the intrinsic 1/f noise. The ion camera chip was fabricated in an unmodified 4-metal 0.35 µm CMOS process and the ionic imaging technology was based on a 64�×64-pixel ion sensitive field effect transistor (ISFET) array. The high-speed and synchronous operation of the 4096 ISFET sensors occupying 715.8×715.8 µm space provided a spatial resolution as low as one pixel. Each pixel contained 4 transistors with 10.2×10.2 µm layout dimensions and the pixels were separated by a 1 µm separation gap. The ion sensitive silicon nitride based passivation layer was in contact with the floating gates of the ISFET sensors. It allowed the capacitive measurements of localised changes in the ionic concentrations, e.g. pH, pNa, on the surface of the chip. The device showed an average ionic sensitivity of 20 mV/pH and 9 mV/pNa. The packaging and encapsulation was carried out using PGA-100 chip carriers and two-component epoxies. Custom designed printed circuit boards (PCBs) were used to provide interface between the ISFET array chip and the data acquisition system. The data acquisition and extraction part of the developed software system was based on LabVIEW, the data processing was carried out on Matlab platform

HPCCP/CAS Workshop Proceedings 1998

This publication is a collection of extended abstracts of presentations given at the HPCCP/CAS (High Performance Computing and Communications Program/Computational Aerosciences Project) Workshop held on August 24-26, 1998, at NASA Ames Research Center, Moffett Field, California. The objective of the Workshop was to bring together the aerospace high performance computing community, consisting of airframe and propulsion companies, independent software vendors, university researchers, and government scientists and engineers. The Workshop was sponsored by the HPCCP Office at NASA Ames Research Center. The Workshop consisted of over 40 presentations, including an overview of NASA's High Performance Computing and Communications Program and the Computational Aerosciences Project; ten sessions of papers representative of the high performance computing research conducted within the Program by the aerospace industry, academia, NASA, and other government laboratories; two panel sessions; and a special presentation by Mr. James Bailey

Soft Robotics: Design for Simplicity, Performance, and Robustness of Robots for Interaction with Humans.

This thesis deals with the design possibilities concerning the next generation of advanced Robots. Aim of the work is to study, analyse and realise artificial systems that are essentially simple, performing and robust and can live and coexist with humans. The main design guideline followed in doing so is the Soft Robotics Approach, that implies the design of systems with intrinsic mechanical compliance in their architecture. The first part of the thesis addresses design of new soft robotics actuators, or robotic muscles. At the beginning are provided information about what a robotic muscle is and what is needed to realise it. A possible classification of these systems is analysed and some criteria useful for their comparison are explained. After, a set of functional specifications and parameters is identified and defined, to characterise a specific subset of this kind of actuators, called Variable Stiffness Actuators. The selected parameters converge in a data-sheet that easily defines performance and abilities of the robotic system. A complete strategy for the design and realisation of this kind of system is provided, which takes into account their me- chanical morphology and architecture. As consequence of this, some new actuators are developed, validated and employed in the execution of complex experimental tasks. In particular the actuator VSA-Cube and its add-on, a Variable Damper, are developed as the main com- ponents of a robotics low-cost platform, called VSA-CubeBot, that v can be used as an exploratory platform for multi degrees of freedom experiments. Experimental validations and mathematical models of the system employed in multi degrees of freedom tasks (bimanual as- sembly and drawing on an uneven surface), are reported. The second part of the thesis is about the design of multi fingered hands for robots. In this part of the work the Pisa-IIT SoftHand is introduced. It is a novel robot hand prototype designed with the purpose of being as easily usable, robust and simple as an industrial gripper, while exhibiting a level of grasping versatility and an aspect comparable to that of the human hand. In the thesis the main theo- retical tool used to enable such simplification, i.e. the neuroscience– based notion of soft synergies, are briefly reviewed. The approach proposed rests on ideas coming from underactuated hand design. A synthesis method to realize a desired set of soft synergies through the principled design of adaptive underactuated mechanisms, which is called the method of adaptive synergies, is discussed. This ap- proach leads to the design of hands accommodating in principle an arbitrary number of soft synergies, as demonstrated in grasping and manipulation simulations and experiments with a prototype. As a particular instance of application of the method of adaptive syner- gies, the Pisa–IIT SoftHand is then described in detail. The design and implementation of the prototype hand are shown and its effec- tiveness demonstrated through grasping experiments. Finally, control of the Pisa/IIT Hand is considered. Few different control strategies are adopted, including an experimental setup with the use of surface Electromyographic signals

First Annual Workshop on Space Operations Automation and Robotics (SOAR 87)

Several topics relative to automation and robotics technology are discussed. Automation of checkout, ground support, and logistics; automated software development; man-machine interfaces; neural networks; systems engineering and distributed/parallel processing architectures; and artificial intelligence/expert systems are among the topics covered

Laboratory Directed Research and Development Program FY 2005 Annual Report

The Oak Ridge National Laboratory (ORNL) Laboratory Directed Research and Development (LDRD) Program reports its status to the U.S. Department of Energy (DOE) in March of each year. The program operates under the authority of DOE Order 413.2A, 'Laboratory Directed Research and Development' (January 8, 2001), which establishes DOE's requirements for the program while providing the Laboratory Director broad flexibility for program implementation. LDRD funds are obtained through a charge to all Laboratory programs. This report describes all ORNL LDRD research activities supported during FY 2005 and includes final reports for completed projects and shorter progress reports for projects that were active, but not completed, during this period. The FY 2005 ORNL LDRD Self-Assessment (ORNL/PPA-2006/2) provides financial data about the FY 2005 projects and an internal evaluation of the program's management process. ORNL is a DOE multiprogram science, technology, and energy laboratory with distinctive capabilities in materials science and engineering, neutron science and technology, energy production and end-use technologies, biological and environmental science, and scientific computing. With these capabilities ORNL conducts basic and applied research and development (R&D) to support DOE's overarching national security mission, which encompasses science, energy resources, environmental quality, and national nuclear security. As a national resource, the Laboratory also applies its capabilities and skills to the specific needs of other federal agencies and customers through the DOE Work For Others (WFO) program. Information about the Laboratory and its programs is available on the Internet at <http://www. ornl.gov/>. LDRD is a relatively small but vital DOE program that allows ORNL, as well as other multiprogram DOE laboratories, to select a limited number of R&D projects for the purpose of: (1) maintaining the scientific and technical vitality of the Laboratory; (2) enhancing the Laboratory's ability to address future DOE missions; (3) fostering creativity and stimulating exploration of forefront science and technology; (4) serving as a proving ground for new research; and (5) supporting high-risk, potentially high-value R&D. Through LDRD the Laboratory is able to improve its distinctive capabilities and enhance its ability to conduct cutting-edge R&D for its DOE and WFO sponsors. To meet the LDRD objectives and fulfill the particular needs of the Laboratory, ORNL has established a program with two components: the Director's R&D Fund and the Seed Money Fund. As outlined in Table 1, these two funds are complementary. The Director's R&D Fund develops new capabilities in support of the Laboratory initiatives, while the Seed Money Fund is open to all innovative ideas that have the potential for enhancing the Laboratory's core scientific and technical competencies. Provision for multiple routes of access to ORNL LDRD funds maximizes the likelihood that novel and seminal ideas with scientific and technological merit will be recognized and supported

Efficient Passive Clustering and Gateways selection MANETs

Passive clustering does not employ control packets to collect topological information in ad hoc networks. In our proposal, we avoid making frequent changes in cluster architecture due to repeated election and re-election of cluster heads and gateways. Our primary objective has been to make Passive Clustering more practical by employing optimal number of gateways and reduce the number of rebroadcast packets