Electromechanical actuators exploit the Lorentz force law to convert electrical energy into rotational or linear mechanical energy. In these electromagnetically induced motions, the electrical current flows through wires that are rigid, and consequently, the types of motion generated are limited. Recent advances in preparing liquid metal alloys permit wires that are flexible. Such wires have been used to fabricate various forms of flexible connections, but very little has been done to use liquid metal as an actuator. In this paper, we propose and have tested a new type of motor using liquid metal conductors in which radial (or breathing) modes are activated.

ABSTRACT:One way to break acoustic reciprocity is to have a moving wave propagation medium. If the acoustic wave vector and the moving fluid velocity are collinear we can use the wave vector shift caused by the fluid flow to break reciprocity. In this paper we investigated an alternative approach in which the fluid velocity enters the differential equation of the system as a cross product term with the wave vector. A circular field where the fluid velocity increases radially has a Coriolis acceleration term. In such a system, the acoustic wave enters from the central wall and exits from the perimeter wall. In this paper, we solved the differential equation numerically and investigated the effect of fluid velocity on the nonreciprocity factor.

In electromechanical actuators Lorentz force law is used to convert electrical energy into rotational or linear mechanical energy. In these conventional electromechanical actuators, rigid wires conducts the electrical current and as such the types of motion generated by these actuators are limited. Recent advances in liquid metal alloys permit designing electrical wires that are stretchable. These flexible wires have been used to fabricate various flexible connections, sensors and antennas. However, there have been very little efforts to use these stretchable liquid metal wires as actuators. Building upon our previous work in this area, we have made a flexible pump which can be used in bio applications. In this design we placed a flexible polymeric substrate filled by liquid metal Galinstan between two permanent magnets. Since the pump should convey the biological cells suspended along the fluid flow, utilizing check valves may increase the risk of clog in the inlet or outlet. Therefore, our design is based on the nozzle/diffuser concept. This new pump can be considered as a peristaltic and valve-less mechanical pumps which utilizes the Lorentz force law as the actuating mechanism.

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