Abstract
A very flexible structure with a tunable stiffness controlled by an external magnetic stimulus is presented. The proposed structure is fabricated using two magnetic-responsive materials, namely a magnetorheological elastomer (MRE) as a skin layer and a magnetorheological fluid (MRF) as a core to fill the void channels of the skin layer. After briefly describing the field-dependent material characteristics of the MRE and MRF, the fabrication procedures of the structure are provided in detail. The MRE skin layer is produced using a precise mold with rectangular void channels to hold the MRF. Two samples are produced, namely with and without MRF, to evaluate the stiffness change attributed to the MRF. A magnetic field is generated using two permanent magnets attached to a specialized jig in a universal tensile machine. The force-displacement relationship of the two samples are measured as a function of magnetic flux density. Stiffness change is analyzed at two different regions, namely a small and large deformation region. The sample with MRF exhibits much higher stiffness increases in the small deformation region than the sample without MRF. Furthermore, the stiffness of the sample with MRF also increases in the large deformation region, while the stiffness of the sample without MRF remains constant. The inherent and advantageous characteristics of the proposed structure are demonstrated through two conceptual applications, namely a haptic rollable keyboard and a smart braille watch.
Highlights
Smart fluids, including electrorheological fluids (ERFs) and magnetorheological fluids (MRFs), can be effectively applied in a number of scenarios, including as an automotive damper and for vibration control in flexible structures
ERF consists of a carrier liquid with fine nonconducting particles, and its apparent viscosity depends heavily on an electric field applied to the fluid domain
The chain-like structures that form under a magnetic with uniform performance, and the scanning electron microscopy (SEM) images of MRF (MRF 140CG, Lord) clearly show that the field cause the behavior of the MRF to shift from a Newtonian liquid to the Bingham model, where particles were randomly distributed the magnetic and have arrangement yield stress is generated within thewithout fluid
Summary
Smart fluids, including electrorheological fluids (ERFs) and magnetorheological fluids (MRFs), can be effectively applied in a number of scenarios, including as an automotive damper and for vibration control in flexible structures. Materials 2020, 13, 953 and MRF are often only used for vibration control of flexible beams and plates because the outer components of smart structures are usually insufficiently soft or flexible. The configuration of a conventional smart structure (i.e., composite) is shown, where the natural frequencies of the ERF or MRF core can be tuned based on the intensity of external stimuli. This tunable property is advantageous for the effective control of unwanted vibrations and is possible by avoiding the resonance problem with a specific magnetic field intensity.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
