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A new application of the genetic algorithm approach is introduced to solve printed circuit board assembly planning problems. The developed genetic algorithm finds the sequence of component placement/insertion and the arrangement of feeders simultaneously, for achieving the shortest assembly time, for three main types of assembly machines. The algorithm uses links (parents) to represent possible solutions and it applies genetic operators to generate new links (offspring) in an iterative procedure to obtain nearly optimal solutions. Examples are provided to illustrate solutions generated by the algorithm.

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A major limitation of using synthetic scaffolds in tissue engineering applications is insufficient angiogenesis in scaffold interior. Bioactive borate glasses have been shown to promote angiogenesis. There is a need to investigate the biofabrication of polymer composites by incorporating borate glass to increase the angiogenic capacity of the fabricated scaffolds. In this study, we investigated the bioprinting of human adipose stem cells (ASCs) with a polycaprolactone (PCL)/bioactive borate glass composite. Borate glass at the concentration of 10 to 50 weight %, was added to a mixture of PCL and organic solvent to make an extrudable paste. ASCs suspended in Matrigel were ejected as droplets using a second syringe. Scaffolds measuring 10x10x1 mm3 in overall dimensions with pore sizes ranging from 100 – 300 µm were fabricated. Degradation of the scaffolds in cell culture medium showed a controlled release of bioactive glass for up to two weeks. The viability of ASCs printed on the scaffold was investigated during the same time period. This 3D bioprinting method shows a high potential to create a bioactive, highly angiogenic three-dimensional environment required for complex and dynamic interactions that govern the cell’s behavior in vivo.

New hybrid 3D structure electrodes with a high aspect ratio are fabricated through extrusionbased additive manufacturing to achieve high mass loading. This new 3D printed battery exhibits both high areal and specific capacity, thus overcoming the trade-off between the two of the conventional laminated batteries. This excellent battery performance is achieved by introducing a hybrid 3D structure that utilizes the benefits of the existing laminated structure and threedimensional interdigitated structure. In addition, conventional battery paste components are used optimally to fit the 3D printing process, which eliminates the need for a complicated solvent preparation process required for a typical 3D printing process for battery applications. Using the CR2032 coin cell, the general assembly problem that occurs at the 3D structured electrodes is solved, which means that the proposed hybrid 3D structure can easily be added to the existing lamination structure. This innovative design and fabrication process demonstrates the high areal energy and power density, which is a critical requirement for energy storage systems in transportation and stationary applications.

The problem of optimal control of robotic manipulators is dealt with in two stages: (1) optimal trajectory planning, which is performed off-line and results in the prescription of the position and velocity of each link as a function of time along a “given” path and (2) on-line trajectory tracking, during which the manipulator is guided along the planned trajectory using a feedback control algorithm. In order to obtain a general trajectory planning algorithm which could account for various constraints and performance indices, the technique of dynamic programming is adopted. It is shown that for a given path, this problem is reduced to a search over the velocity of one moving manipulator link. The design of the algorithm for optimal trajectory planning and the relevant computational issues are discussed. Simulations are performed to test the effectiveness of this method. The use of this algorithm in conjunction with an on-line controller is also presented.