Magnetorheological (MR) fluids are materials characterized as "intelligent" since their rheological properties may be controlled by the excitation of an external magnetic field. The application of the latter brings the fluid from a liquid to a semi-solid state. Due to their properties, these materials are widely used, among others, in biomedical applications. In the present work, multiple MR valves are incorporated as pressure limiters in a smart biomedical insole for diabetic patients. The diabetics are affected by high plantar pressures that cause ulceration and frequently, as a consequence of ulceration, lower extremity amputation. This novel insole aims at the active plantar pressure offloading. Thus, considering the small size of the insole, the number of the valves, as well as the high plantar pressures that reach up to 1 MPa on diabetic feet, a study is performed on optimizing the design of the MR valve, exploiting the Design of Experiments (DoE) techniques. Moreover, a testbench is presented for the examination of pressure self-sensing capabilities of the valves, with a future goal to integrate them in the design optimization and acquire a sensorless system.
The conventional development of tubular generators for applications intended to harvest energy using vehicle suspension systems is faced with the critical challenge of increasing the power harvested for a given space. Conventional optimal designs of machine dimensions have improved both output power and output power density, but the actual values are still relatively small. Recently, we proposed a novel tubular generator structure that combines a mechanical shock absorber and an electrical generator. An innovative permanent magnet structure using both Halbach array and iron spacers (a hybrid-type) was applied. The high relative permeability of the iron material significantly improved the performance of the proposed generator in comparison with conventional models. A prototype was fabricated and experimentally validated via simulation.
In this paper, a modification of the dual-segment permanent magnet (PM) Halbach array is investigated to improve the performance of the tubular linear machine, in terms of flux density and output power. Instead of a classical Halbach array with only radial and axial PMs, the proposed model involves the insertion of mig-magnets, which have a magnetized angle shifted from the reference magnetized angles of axial and radial PMs. This structure leads to the elimination of flux leakage and the concentration of flux linkage in middle of the coil; therefore, the output power is increased by 13.2%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.