Electrostatically actuated polysilicon beams fabricated in the MUMPs process are studied, with an emphasis on the behavior when the beam is in contact with an underlying silicon nitride dielectric layer. Detailed 2D electromechanical simulations, including the mechanical effects of stepups, stress-stiffening and contact, as well as the electrical effects of fringing fields and finite beam thick...

A dielectric elastomer transducer is a deformable capacitor, and is under development as a sensor, actuator, or generator. Among various geometric configurations, laterallyconstrained transducer, also known as pure-shear transducer, is easy to implement and effective to couple mechanical force and electrical voltage. This analytical study reveals that lateral pre-stretch enhances actuation, far...

A novel approach for nanoscale imaging and characterization of the orientation dependence of electromechanical properties-vector piezoresponse force microscopy (Vector PFM)-is described. The relationship between local electromechanical response, polarization, piezoelectric constants, and crystallographic orientation is analyzed in detail. The image formation mechanism in vector PFM is discussed...

The future More Electric Aircraft (MEA) technology focus on increasing the use of electrical equipment to a larger extent, e.g. replacing conventional hydraulic and pneumatic actuators with electromechanical or electro hydrostatic actuators to reduce weight, cost and maintenance. Advances in enabling technologies of electric power generation, distribution, and utility equipment have made the us...

This paper discusses a state space estimation for an electromechanical actuator valve using extended Kalman filter (EKF). A proposed actuator model includes a Tustin’s friction model with strong nonlinearities, hence it represents an accurate model for describing the friction phenomenon in an electromechanical actuator valve. At first the state equations of the model were converted into a time-...

Background: Asthma is a predisposing factor for the development of atrial fibrillation. Asthma disturbs the electrophysiology in the right and left atrium. The aim of this study was to evaluate atrial electromechanical delay by coupling obtained from tissue Doppler imaging (TDI) in children. Methods: A cross-sectional study was conducted on 50 patients with Bronchial Asthma, compared with 50 hea...

The PEA (Physiologically Explicit Approach) cotton model is a mechanistic, L-system (Hanan 1997) model of growth processes utilising carbohydrate production, translocation and allocation. In Thornby et al (2003), we used the PEA cotton model to investigate the phenomenon of compensatory growth in partially defoliated cotton seedlings. Experiments showed that the development rate of cotton seedl...

Lipid membranes are insulators and capacitors, which can be charged by an external electric field. This phenomenon plays an important role in the field of electrophysiology, for instance when describing nerve pulse conduction. Membranes are also made of polar molecules meaning that they contain molecules with permanent electrical dipole moments. Therefore, the properties of membranes are subjec...

Ionic actuators have attracted attention due to their remarkably large strain under low-voltage stimulation. Because actuation performance is mainly dominated by the electrochemical and electromechanical processes of the electrode layer, the electrode material and structure are crucial. Here, we report a graphitic carbon nitride nanosheet electrode-based ionic actuator that displays high electr...