This paper presents the mechanical design and modeling of an active segment of a bioinspired piezocomposite aquatic pump. The design and analysis is based on an electromechanical Euler-Bernoulli beam model. The self-contained propulsion/pumping system is composed of a series of piezo-active soft cymbal-like segments that are connected by passive soft films. By applying coordinated excitations for expansion and contraction to different active segments, the design creates a traveling wave along the pump axis, which in return propels the fluid to generate a unidirectional thrust force. In the model, the insulation and mechanical properties of the waterproofing sealant layer are considered. Using the proposed electromechanical model, a parametric analysis is conducted to understand the effectiveness of the cymbal-like piezocomposite active segment. Two performance metrics are considered, including the area change of the enclosed by the cymbal-like segment, and the work done by the actuators. The optimal structural parameters of the piezocomposite pump are decided by these performance metrics.

This paper focuses on the design and development of a bio-inspired mobile robot using piezoelectric transducers as drives. The design of the device aimed to imitate the trajectory movement of a crawl-like animal. Design constraints as producing controlled movement with piezoelectric transducer, as well as the combination of multiple piezoelectric patches into one mobile robot are presented in their practical aspects. The robot uses 2 piezoelectric transducers as main drives, but also as main structural components of the device. The patches are connected with a thin light rod, and the kinematic of movement is achieved with 4 tiny wooden legs connected on each of the patches. The project investigates the possibility and effectiveness of the piezoelectric transducers for movement of the bio-inspired mobile robot. From conceptual development, to the mechanical design and control, the mobile robot is used to test different trajectories of movement. Ni RIO Evaluation kit has been incorporated as a real-time and FPGA control platform for the mobile robot while using Labview programing environment. To accomplish complex trajectories of movement the velocity of the robot was measured for straight line and rotation of the robot.

Passive control of cooling processes is in designs best interest. Coolant medium flow to hot components must be kept at minimum acceptable level from lifting perspective to achieve maximum process efficiency. Required cooling of the hot components depends directly on engine power setting, which in general requires a relative complex system for monitoring critical parameters and adjusting coolant’s amount with engine load. Concerning the operation reliability, pseudoplastic shape memory alloys offer a high simplicity in the design of adjustment mechanisms with large operating displacements. As the shape memory effect is induced by temperature changes, the behavior of shape memory actuators and therefore the coolant’s amount can be adjusted to the load conditions of the engine by using appropriate shape memory materials. In this paper an actuator based on a shape memory membrane using the extrinsic two-way effect is presented to vary the cross-sectional area of a cooling air channel with respect to the engine operation. The reset of the mechanism after one temperature cycle of heating and cooling is realized by using a leaf spring element, which is in varing mechanical contact with the shape memory membrane depending on the hysteresis of the entire system. Maximum displacements of the system are attained for spring forces between the force generated by the shape memory membrane in the martensitic and austenitic state. Thus, the system mechanism exhibits two non-linearities of pseudoplastic shape memory characteristic and contact mechanics with friction. For this purpose experimental investigations were carried out to acquire the fundamental force displacement behavior of the shape memory membrane to design the optimal shape of the leaf spring element. The forces required to deform the shape memory membrane in the martensitic and austenitic state were measured with respect to the membranes displacement using a load cell and a linear variable differential transformer. The displacements of the membrane were introduced using a linear bearing system. The calculations for the design of an optimal leaf spring and especially its initial shape were carried out using a discrete multi body system consisting of beam elements and torsional springs. The leaf spring with the calculated optimal shape was fabricated and incorporated into the system. The displacement behavior of the system during heating and cooling was measured using an optical distance sensor. For the analyzed temperature range up to 100 °C, the paper describes the methodological appropriacy and relevance towards the application domain for evaluated temperatures.

While the usefulness of small scale prototypes for harvesting the energy of waves have already been demonstrated, the utilization of the capability of flow energy in rivers based on electroactive polymers is still a significant challenge. To harvest the energy of flowing waters, a novel flow energy converter based on a simple and environmentally sustainable mechanical design is developed, consisting of an elastomeric tube with a closing mechanism at the outlet side. Because the stationary stretch of the tube is comparably small, the tube has to be operated in resonance, which offers a high resonant magnification of the tube deformation. The resonant operation can be obtained, when the tube is closed rapidly and a shock wave is induced into the tube, which is often referred to as water hammer. Based on a small-scale prototype, this expected mechanical behavior of the tube was demonstrated.