Binayak Bhandari

Fabrication of wrist-like SMA-based actuator by double smart soft composite casting

A new manufacturing method for smart soft composite (SSC) actuators that consists of double casting a SSC actuator to produce an actuator with non-linear shape memory alloy (SMA) wire positioning is proposed. This method is used to manufacture a tube-shaped SSC actuator in which the SMA wires follow the curvature of the tube and is capable of pure-twisting deformations while sustaining a cantilever load. The concept is tested by measuring the maximum twisting angle and a simple control method is proposed to control the twisting angle of the actuator. Then, a soft robotic wrist with a length of 18 cm is built, its load-carrying capability is tested by measuring the cantilever force required for deforming the actuator, and its load-carrying capability during actuation is tested by loading one end with different objects and actuating the actuator. This wrist actuator shows good repeatability, is capable of twisting deformations up to 25° while holding objects weighing 100 g, and can sustain loads above 2 N without undergoing buckling.

A shape memory alloy–based soft morphing actuator capable of pure twisting motion

This article introduces a novel design for a soft morphing actuator capable of pure twisting motion through a pair of shape memory alloy wires embedded in a polydimethylsiloxane matrix at constant and opposite eccentricity across the cross section in opposite directions. This report introduces the design of the actuator, the manufacturing method, and experimental results for the twisting angle and twisting force when varying the dimensions of the matrix of the actuator. Afterward, a simple model is applied to verify the effect of matrix dimensions on the twisting angle of the actuator. The results show that there is an optimal actuator thickness for both the twisting angle and the twisting force of the actuator, that there is a trade-off between the twisting angle and the twisting force for the actuator’s thickness, and that a longer length is better for both metrics within the tested dimensions.

Formation Strategy of Renewable Energy Sources for High Mountain Off-grid System Considering Sustainability

Characteristics of off-grid hybrid renewable energy sources for high mountain villages are discussed. Considering reliability of electric power generation, Photovoltaic (PV)-wind hybrid and PV-hydro hybrid system are suggested. Connecting two or more villages with these hybrid systems, an extended hybrid off-grid can be formed. Sustainability of entire system is important in design of off-grid system, and income generation of the village people using the electricity should be considered.

Energy Analysis of Micro-drilling Process Used to Manufacture Printed Circuit Boards

Energy savings are becoming a new focus in the industrial sector because of environmental concerns. In order to establish an energy-saving strategy for micro-drilling, it is necessary to consider all aspects of the drilling procedure, including the post-drilling process. This study analyzed micro-drills with diameters of 400 μm. Process parameters, such as the rotational speed of the spindle and in-feed, were controlled, and the energy consumption of each process was measured. Operators can use the results to make decisions on process parameters and whether to perform a de-burring process. Ultimately, an effective energy-saving strategy can be devised for micro-drilling.