This study describes a new simulator that provides haptic biofeedback to help manual wheelchair users gain a more effective propulsion pattern. Propulsion effectiveness is measured using the mechanical effective force (MEF). The simulator implements a dynamic model that replicates overground propulsion conditions. Haptic biofeedback increases the feeling of rolling resistance if the user’s MEF ...

Miniature and energy efficient propulsion systems hold the key to maturing the technology of swimming microrobots. In this paper, two new methods of propulsion inspired by the motility mechanism of prokaryotic and eukaryotic microorganisms are proposed. Hydrodynamic models for each of the two methods are developed and the optimized design paramteres for each of the two propulsion modes are demo...

This study analyzed the effect of rear-wheel position on seating comfort and mobility efficiency. Twelve randomly selected paraplegic wheelchair users participated in the study. Wheelchairs were tested in two rear-wheel positions while the users operated the wheelchair on a treadmill and while they worked on a computer. Propulsion efficiency, seating comfort, and propulsion qualities were regis...

NASA’s Hyper-X Research Vehicle will provide a unique opportunity to obtain data on an operational airframe integrated scramjet propulsion system at true flight conditions. The airframe integrated nature of the scramjet engine with the Hyper-X vehicle results in a strong coupling effect between the propulsion system operation and the airframe’s basic aerodynamic characteristics. Comments on gen...

Marangoni propulsion is a form of locomotion wherein an asymmetric release of surfactant by a body located at the surface of a liquid leads to its directed motion. We present in this paper a mathematical model for Marangoni propulsion in the viscous regime. We consider the case of a thin rigid circular disk placed at the surface of a viscous fluid and whose perimeter has a prescribed concentrat...

Bubble-propelled catalytic micromotors have recently been attracting much attention. A bubble-propulsion mechanism has the advantage of producing a stronger force and higher speed than other mechanisms for catalytic micromotors, but the nature of the fluctuated bubble generation process affects the motions of the micromotors, making it difficult to control their motions. Thus, understanding of ...

The motion of self-propelled tubular micro- and nanojets has so far been achieved by bubble propulsion, e.g., O2 bubbles formed by catalytic decomposition of H2O2, which renders future biomedical applications inviable. An alternative self-propulsion mechanism for tubular engines on the nanometer scale is still missing. Here, we report the fabrication and characterization of bubble-free propelle...

The ultrasonic propulsion of rod-shaped nanomotors inside living HeLa cells is demonstrated. These nanomotors (gold rods about 300 nm in diameter and about 3 mm long) attach strongly to the external surface of the cells, and are readily internalized by incubation with the cells for periods longer than 24 h. Once inside the cells, the nanorod motors can be activated by resonant ultrasound operat...

Understanding propulsion and adaptation to speed requirements is important in determining appropriate therapies for gait disorders. We hypothesize that adaptations for changing speed requirements occur primarily at the hip. The slow, normal and fast gait of 24 healthy young subjects was analyzed. The linear power was analyzed at the hip joint. The anterior-posterior and vertical induced acceler...

A novel multi-mode spacecraft propulsion concept is presented. The concept combines chemical monopropellant and electric pulsed inductive thruster technology to include shared propellant and shared conical nozzle. Geometry calculations show that existing conical pulsed inductive thruster experiments are typical of large (1000-4000 N) chemical monopropellant thruster nozzles. Performance and pro...