Applied Mechanics and Materials Vols. 592-594

Abstract: A three-dimensional microfluidic biosensor has been successfully designed using a low temperature co-fired ceramic (LTCC) technology. This microfluidic sensor consists of mixing, focusing and measuring region. The mixing region is a rectangular shaped channel, to enable the complete mixing of sample and buffered saline solution. An electrode pair in the focusing region uses negative dielectrophoretic forces to direct the cells from all directions of the channel towards the center. The measuring region consists of eleven pairs of gold plated electrodes to measure the change in impedance whenever a cell passes through it. The layout of the design is made using AUTOCAD tool and simulated using COMSOL Multiphysics. The results demonstrate the mixing efficiency of two fluids for different velocities.

Abstract: In this paper, computational savings by an Haar wavelet method for state analysis of disk-drive system is presented. Based upon useful properties of Haar functions like operational matrix of integration, analysis of disk drive system is done. Computational savings in system analysis achieved with the non-recursive operational matrix as compared to recursive operational matrix have been verified using MATLAB PROFILER for different resolutions.

Abstract: Snake robots have high degrees of freedom and can move on any kind of environment by suitably adjusting itself. In order to serve this purpose, a snake robot with two sets of three revolute joint mechanism was developed to exhibit concertina motion. There are rotating disks at the end of the segments which enables side winding motion. By the combination of these two motions, the snake robot can traverse on flat surfaces and even on slopes. The snake robot was first drafted and then modeled. Then the mechanism was simulated and stress analysis was done for it. Finally the design was implemented and the snake robot was made in reality.

Abstract: This work mainly aims to explore the actual load, fillet and contact stresses induced during a mesh cycle in a spur gear tooth. As the mesh stiffness differs at different contact points along the path of contact, it significantly affects the load sharing between the simultaneously meshed contact pairs hence stresses. Comparative study has been made between existing symmetric spur gear pair used in light motor vehicle gear box and asymmetric spur gear. Finite element multi pair contact model has been used to explore the load sharing behavior and related stresses in this work.

Abstract: The paper presents a technique to simulate driving mechanism in automotive seat height adjuster. Simulation is done using multi-body dynamic software ADAMS. The exercise included development of an accurate model using design tool. The design model is then converted to simulation tool. Selected operating force is applied and simulated. The area of focus is forces between two gear meshing parts. Simulation result is then compared with analytical calculation. Validation is also made for the considered factor of safety.

Abstract: Deriving inspiration from the propulsion methods of squids, a pulsatile jet propulsion system is adopted in a robotic model. A squid-like direction control mechanism, which can direct the jet along any direction on a hemispherical work volume, is also implemented. To obtain a suitable robot velocity (_v) and a propulsive efficiency (η_p) for testing this mechanism, the stroke ratio (L/D) and outlet diameter are varied and the _v and the η_p of various alternatives are estimated experimentally using vision analysis. A Stroke ratio of 3.78 and an outlet diameter of 25.4 mm were found suitable and employed for testing the mechanism. When the jet is deflected by 60° in the horizontal plane, the robot rotates about its centroid, signifying excellent maneuverability. Reverse motion was also demonstrated by removing inlet valves and blocking the outlet through the direction control mechanism. The performance of the direction control mechanism indicates that the robotic model was a feasible alternative to conventional screw-propelled aquatic robots.

Abstract: The aim of this paper is to determine the effect on direct design asymmetric high contact ratio spur gear based on tooth load sharing. A unique Ansys parametric design language code is developed for this study. The load sharing based bending and contact stresses are determined for different drive side contact ratios. In addition to that the location of critical loading point is determined. Because the critical loading point for high contact ratio spur gear not lies on fixed point like normal contact ratio spur gears namely highest point of single tooth contact. In conclusion an increase in drive side contact ratio leads to increase in the load sharing based bending stress and decrease in the contact stress at the critical loading point.

Abstract: In the immediate surroundings of our daily life, we can find a lot of places where the energy in the form of vibration is being wasted. Therefore, we have enormous opportunities to utilize the same. Piezoelectric character of matter enables us to convert this mechanical vibration energy into electrical energy which can be stored and used to power other device, instead of being wasted. This work is done to realize both actuator and sensor in a cantilever beam based on piezoelectricity. The sensor part is called vibration energy harvester. The numerical analyses were performed for the cantilever beam using the commercial package ANSYS and MATLAB. The cantilever beam is realized by taking a plate and fixing its one end between two massive plates. Two PZT patches were glued to the beam on its two faces. Experiments were performed using data acquisition system (DAQ) and LABVIEW software for actuating and sensing the vibration of the cantilever beam.

Abstract: This paper presents a new design of a 3-RRR planar manipulator with non-planar legs. In contrast to the conventional 3-RRR planar parallel mechanism, the links are not planar. They are elevated above the X-Y plane and non planar legs are constructed. The kinematics of this model is realized on a common projected plane and traced back to its elevated position. The moment of inertia for the inclined links is computed. A stiffness model is established for the proposed design of 3-RRR manipulator and compared with a conventional 3-RRR planar manipulator. The analysis shows how the proposed design has better stiffness along all the three directions of motion.

Abstract: The torque motor is a precision mechatronic component used to convert low electric signal into linear mechanical displacement of the Jetpipe. Such torque motors are categorized under multi disciplinary engineering systems, which are complex in nature and also induces challenges to integrate with hydraulic system. This paper applies model-based system design approach of jetpipe servovalve torque motor to study the effect of critical parameters like armature length and air gap, feedback spring stiffness, and flexure tube stiffness on the dynamic performance of the were studied.