A scheme for active control of nonlinear vibration of space-structures, wherein each member is modeled as a beam-column, is presented. The expressions for shear stresses transmitted to the structural member by the distributed segmented piezo-electric actuators, which are bonded on the surfaces of the member, are derived in the general case in which the structural member is subjected to moments,...

Composite materials are a very important class of engineering materials with great properties and applications in a variety of complex structures. The correct design of such structures requires adequate analysis and, in particular, adequate and accurate models for simulation with numerical tools. Piezoelectric materials can convert mechanical energy into electric energy and vice-versa and are b...

This paper discusses a number of recent findings in connection with ion-exchange polymer-noble metal composites (IPMC) as biomimetic sensors and actuators. These smart composites exhibit characteristics of both actuators and sensors. Strips of these composites can undergo large bending and flapping displacement if an electric field is imposed across their thickness. Thus, in this sense they are...

A weakly-singular form of the piezoelectric boundary integral equation (BIE) formulation is introduced in this paper, which eliminates the calculation of any singular integrals in the piezoelectric BIE. The crucial question of whether or not the piezoelectric BIE will degenerate when applied to crack and thin shell-like problems is discussed. It can be shown analytically that the conventional B...

A better understanding of how actuator design supports locomotor function may help develop novel and more functional powered assistive devices or robotic legged systems. Legged robots comprise passive parts (e.g., segments, joints and connections) which are moved in a coordinated manner by actuators. In this study, we propose a novel concept of a hybrid electric-pneumatic actuator (EPA) as an e...

In multilayer ferroelectric actuators, electrode edges are the main source of fracture due to the generation of non-uniform electric fields in their vicinity. The electric fields, in turn, induce incompatible strain fields and hence concentrated stresses, which may cause the ceramic to crack. In this paper, the crack initiation from the electrode edges is simulated using a phase-field model. Th...

Biological cells regulate their biochemical behavior in response to mechanical stress present in their organism. Most of the available cell cultures designed to study the effect of mechanical stimuli on cells are cm area, far too large to monitor single cell response or have a very low throughput. We have developed two sets of high throughput single cell stretcher devices based on dielectric el...

Data from multiple sensors and actuators has been recorded from December 2001 to March 2008 at the LESO-PB building of the EPFL campus, using the EIB/KNX bus standard. Sensors and actuators provided data on room temperature, presence, lighting level, windows opening, blinds position, electric lights and heating power. Weather data has also been collected and includes ambient temperature, solar ...