In this paper, we propose a tiny haptic knob that creates torque feedback in consumer electronic devices. To develop the proposed haptic knob, we use a magnetorheological (MR) fluid. When an input current is applied to a solenoid coil, a magnetic field causes a change in the MR fluid’s viscosity. This change allows the proposed haptic knob to generate a resistive torque. We optimize the structure of the haptic knob, in which two operating modes of MR fluids contribute to the actuation simultaneously. We conduct magnetic path simulation and resistive torque simulation using the finite element method and perform experiments to measure the resistive torque and its torque rate according to the rotational speed and applied current. The results show that the proposed haptic knob generates sufficient torque feedback to stimulate users and creates a variety of haptic sensations.
Existing soft actuators for adaptive microlenses suffer from high required input voltage, optical loss, liquid loss, and the need for assistant systems. In this study, we fabricate a polyvinyl chloride-based gel using a new synergistic plasticization method to achieve simultaneously a high optical transparency and an ultrasoft rubber-like elastic behavior with a large voltage-induced deformation under a weak electric field. By compressing the smooth gel between two sets of annular electrodes, a self-contained biconvex microlens is realized that is capable of considerable shape changes in the optical path. Each surface of the dual-curvature microlens can be independently adjusted to focus or scatter light to capture real or virtual images, yield variable focal lengths (+31.8 to −11.3 mm), and deform to various shapes to improve aberrations. In addition to simple fabrication, our microlens operates silently and consumes low power (0.52 mW), making it superior to existing microlenses.
This paper presents a magneto-rheological (MR) actuator that can be easily inserted into haptic shoes and can haptically simulate the material properties of the ground. To increase the resistive force of the proposed actuator, we designed a movable piston having multiple operation modes of MR fluids. Further, the design of a solenoid coil was optimized to maximize the resistive force in a limited-sized MR actuator. Simulations were conducted to predict the actuation performance and to show that the magnetic flux flows well by forming a closed loop in the proposed actuator. The quantitative evaluation of the proposed actuator was investigated by measuring the resistive force as a function of the input current and its pressed depth. From the result, we found that the proposed actuator can create over 600 N by adjusting the input current.
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.