Compared to non-amputees, above knee amputees expend significantly more metabolic energy. This is a result of the passive nature of most knee prostheses, as the development of clinically successful powered knee prostheses has remained a challenge. The addition of powered elements, such as electric motors, allow prosthetic knees to more closely emulate natural knee biomechanics. However, the add...

The main objective of this study is to reduce optimal vibration suppression of Timoshenko beam under non-periodic step and impulse inputs. Cantilever beam was modeled by Timoshenko theory and finite element numerical method. Stiffness (K), mass (M), and damping (C) matrices are extracted. Then, in order to control structure vibration, piezoelectric patches were used due to simultaneous dual beh...

This paper theoretically analyzes a dielectric elastomer tube actuator DETA . Subject to a voltage difference between the inner and outer surfaces, the actuator reduces in thickness and expands in length, so that the same voltage will induce an even higher electric field. This positive feedback may cause the actuator to thin down drastically, resulting in electrical breakdown. We obtain an anal...

A new type of permanent magnet actuator driven by electromagnetic repulsive force in breaking course and electromagnetic attraction force during closing course is presented in this paper, and the static and dynamic characteristics for contactor with this new type actuator are mainly focused on by simulation and experiment simultaneously. Firstly, the static electromagnetic attraction force in c...

The single crystal Cu-Al-Ni alloys became generally commercialized. It can be observed that response time of any single crystal Cu-Al-Ni-based shape memory alloy (SMA) actuator is greater than the necessary when it is used for human prosthesis. Moreover, the electrical SMA actuator type with better performance than the thermal one is very problematic for this type of crystal due to its low elec...

The structural scheme of an electromagnetoelastic actuator for nano biomechanics is found. has difference in the visibility energy conversion from Cady and Mason electrical equivalent circuits a piezo vibrator. electromagnetoelasticity equation differential are solved to construct actuator. obtained by using reverse direct piezoelectric effects. transfer functions written

The Inertially Stabilized Rifle is a new stabilized rifle system that can eliminate the disturbances induced by the shooter. Recurve actuator is used in this system to provide the precise movement of the rifle barrel. In such a portable device, only low voltage electrical sources are available yet the piezoelectric actuator needs high voltage to drive the actuator. The actuators consume little ...

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...

Piezoelectric actuator has been increasingly used in MEMS system due to its advantage of generality and flexibility. A flextensional actuator consist of a piezoceramic device, which can convert electrical energy into mechanical energy and vice versa, and a flexible mechanical structure, which can convert and amplify the output piezoceramic displacement in the desired direction and magnitude. A ...

A theory with experimental verifications has been developed to investigate the nonlinear behavior of comb drive actuators under applied external electrical potential and Joule heating effects. The nonlinear behavior originates from coupled effects of the beam structure under applied electrical potential with electrostatically induced tensile stress and thermally induced compressive stress. Deta...