Chemical Power for Microscopic Robots in Capillaries

The power available to microscopic robots (nanorobots) that oxidize bloodstream glucose while aggregated in circumferential rings on capillary walls is evaluated with a numerical model using axial symmetry and time-averaged release of oxygen from passing red blood cells. Robots about one micron in size can produce up to several tens of picowatts, in steady-state, if they fully use oxygen reaching their surface from the blood plasma. Robots with pumps and tanks for onboard oxygen storage could collect oxygen to support burst power demands two to three orders of magnitude larger. We evaluate effects of oxygen depletion and local heating on surrounding tissue. These results give the power constraints when robots rely entirely on ambient available oxygen and identify aspects of the robot design significantly affecting available power. More generally, our numerical model provides an approach to evaluating robot design choices for nanomedicine treatments in and near capillaries.Comment: 28 pages, 7 figure

Distributed Control of Microscopic Robots in Biomedical Applications

Current developments in molecular electronics, motors and chemical sensors could enable constructing large numbers of devices able to sense, compute and act in micron-scale environments. Such microscopic machines, of sizes comparable to bacteria, could simultaneously monitor entire populations of cells individually in vivo. This paper reviews plausible capabilities for microscopic robots and the physical constraints due to operation in fluids at low Reynolds number, diffusion-limited sensing and thermal noise from Brownian motion. Simple distributed controls are then presented in the context of prototypical biomedical tasks, which require control decisions on millisecond time scales. The resulting behaviors illustrate trade-offs among speed, accuracy and resource use. A specific example is monitoring for patterns of chemicals in a flowing fluid released at chemically distinctive sites. Information collected from a large number of such devices allows estimating properties of cell-sized chemical sources in a macroscopic volume. The microscopic devices moving with the fluid flow in small blood vessels can detect chemicals released by tissues in response to localized injury or infection. We find the devices can readily discriminate a single cell-sized chemical source from the background chemical concentration, providing high-resolution sensing in both time and space. By contrast, such a source would be difficult to distinguish from background when diluted throughout the blood volume as obtained with a blood sample

Acoustic Communication for Medical Nanorobots

Communication among microscopic robots (nanorobots) can coordinate their activities for biomedical tasks. The feasibility of in vivo ultrasonic communication is evaluated for micron-size robots broadcasting into various types of tissues. Frequencies between 10MHz and 300MHz give the best tradeoff between efficient acoustic generation and attenuation for communication over distances of about 100 microns. Based on these results, we find power available from ambient oxygen and glucose in the bloodstream can readily support communication rates of about 10,000 bits/second between micron-sized robots. We discuss techniques, such as directional acoustic beams, that can increase this rate. The acoustic pressure fields enabling this communication are unlikely to damage nearby tissue, and short bursts at considerably higher power could be of therapeutic use.Comment: added discussion of communication channel capacity in section

Using Surface-Motions for Locomotion of Microscopic Robots in Viscous Fluids

Microscopic robots could perform tasks with high spatial precision, such as acting in biological tissues on the scale of individual cells, provided they can reach precise locations. This paper evaluates the feasibility of in vivo locomotion for micron-size robots. Two appealing methods rely only on surface motions: steady tangential motion and small amplitude oscillations. These methods contrast with common microorganism propulsion based on flagella or cilia, which are more likely to damage nearby cells if used by robots made of stiff materials. The power potentially available to robots in tissue supports speeds ranging from one to hundreds of microns per second, over the range of viscosities found in biological tissue. We discuss design trade-offs among propulsion method, speed, power, shear forces and robot shape, and relate those choices to robot task requirements. This study shows that realizing such locomotion requires substantial improvements in fabrication capabilities and material properties over current technology.Comment: 14 figures and two Quicktime animations of the locomotion methods described in the paper, each showing one period of the motion over a time of 0.5 milliseconds; version 2 has minor clarifications and corrected typo

Acoustic Communication for Medical Nanorobots

Communication among microscopic robots (nanorobots) can coordinate their activities for biomedical tasks. The feasibility of in vivo ultrasonic communication is evaluated for micron-size robots broadcasting into various types of tissues. Frequencies between 10MHz and 300MHz give the best tradeoff between efficient acoustic generation and attenuation for communication over distances of about 100 microns. Based on these results, we find power available from ambient oxygen and glucose in the bloodstream can readily support communication rates of about 10,000 bits/second between micron-sized robots. We discuss techniques, such as directional acoustic beams, that can increase this rate. The acoustic pressure fields enabling this communication are unlikely to damage nearby tissue, and short bursts at considerably higher power could be of therapeutic use.Comment: added discussion of communication channel capacity in section

Action Potential Monitoring Using Neuronanorobots: Neuroelectric Nanosensors

Neuronanorobotics, a key future medical technology that can enable the preservation of human brain information, requires appropriate nanosensors. Action potentials encode the most resource-intensive functional brain data. This paper presents a theoretical design for electrical nanosensors intended for use in neuronanorobots to provide non-destructive, in vivo, continuous, real-time, single-spike monitoring of action potentials initiated and processed within the ~86 × 109 neurons of the human brain as intermediated through the ~2.4 × 1014 human brain synapses. The proposed ~3375 nm3 FET-based neuroelectric nanosensors could detect action potentials with a temporal resolution of at least 0.1 ms, enough for waveform characterization even at the highest human neuron firing rates of 800 Hz.The principal author (NRBM) thanks the “Fundação para a Ciência e Tecnologia” (FCT) for their financial support of this work (grant SFRH/BD/69660/2010).info:eu-repo/semantics/publishedVersio

The Natural Way To Learn: Learn Without Learning

Natural learning ways currently used to accelerate the velocity of learning are reviewed, including Selman’s MEDICASA model with his platoon system of participatory responses---all demonstrating innovative multi-sensory, multi-learning skills.  To augment persuasion and articulation ability of business school students, stand-up comedy is used (University of Chicago).  Song writing, storytelling and improvisation (Vanderbilt University-Owens Management), and for Shakespearean motivation for other management skills at the corporate executive level (Northrup Grumman).  Food “chow-down”, before and during classes, including pizzas, soyburgers and chocolate candy, for relaxation and memory stimulation and retention.  The aromatherapy path to soft learning, the path of music and subliminal sound--Mozart effect and silent sound--and other multi-sensory aids and teaching techniques to activate all the senses for learning---Key for three senses, but strive for five!  Other learning techniques include Selman’s Universal Method (SUM) of breaking large problems into manageable parts or patches.  His MEDICASA Model for developing models for multi-learning in various venues will be demonstrated. Another approach is to have abstract ideas in the sciences translated into physical learning aids, or robotic device, or toys--- where the kernel of the analogies can be retained for comprehending differing situations in the present, and for future metaphors.  Learning aids, toys, robotic devices and simulation techniques will be explored for state-of-the-art reinforcement of ideas and innovative concepts at this point in time.  When Al Gross (a.k.a. Phineas Thaddeus Veeblefetzer) passed away at the end of the last millennium, the gizmos he designed and had patented---just for the fun of it!-- like Dick Tracy’s two-way wrist radio, the walkie-talkie, and other wireless wonders still have a revered resting place in the heart of our fun memories.  Learning can be reinforced in many ways.  But learning without play is difficult, grim and boring presentations.  It may be the major failing of our educational system

The Changing Scientific and Technological Basis of the CBW Proliferation Problem

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