1,015 research outputs found
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
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
Bioinspired NEMS-Prospective of Collaboration with Nature
The fields of micro- and nanomechanics are strongly interconnected with the development of micro-electro-mechanical (MEMS) and nano-electro-mechanical (NEMS) devices, their fabrication and applications. This article highlights the biomimetic concept of designing new nanodevices for advanced materials and sensing applications
Pushing bacterial biohybrids to in vivo applications
Bacterial biohybrids use the energy of bacteria to manipulate synthetic materials with the goal of solving biomedical problems at the micro- and nanoscale. We explore current in vitro studies of bacterial biohybrids, the first attempts at in vivo biohybrid research, and problems to be addressed for the future
- …