Issue link: https://iconnect007.uberflip.com/i/582861
74 The PCB Magazine • October 2015 orders. Favorable selections are most double- sided product, LED product and multitude of multilayer builds. With correct scheduling, load balancing the management attribute solves itself. With prop- er future foresight, staffing can be adjusted to process varying loading cycles. Strong mainte- nance/PM programs attack the machine attri- bute while a strong training/cross-training pro- gram attacks the "person" attribute. Communication, scheduling and proper loading in our exercise are the main influences in ET cycle time. Keeping these variables under control can reduce ET cycle time measurably while also providing the needed sprint when Mr. Murphy makes a visit upstream. PCB TesTing Todd BREAKING THE BOTTLENECK: ELECTRICAL TEST CyCLE TIME REDUCTION Todd Kolmodin is the vice president of quality for gardien Services uSa, and an expert in electrical test and reliability issues. To read past columns, or to contact the author, click here. using components made from smart shape- memory materials with slightly different re- sponses to heat, researchers have demonstrat- ed a four-dimensional printing technology that allowed creation of complex self-folding structures. The technology, developed by researchers at the georgia institute of Technology and the Singapore university of Technology and Design (SuTD), could be used to create 3-D structures that sequentially fold themselves from compo - nents that had been flat or rolled into a tube for shipment. The components could respond to stimuli such as temperature, moisture or light in a way that is precisely timed to create space structures, deployable medical devices, robots, toys and range of other structures. The researchers used smart shape memory polymers (SmPs) with the ability to remem - ber one shape and change to another pro- grammed shape when uniform heat is applied. The ability to create objects that change shape in a controlled sequence over time is enabled by printing multiple materials with different dynamic mechanical properties in prescribed patterns throughout the 3-D object. When these components are then heated, each SmP responds at a different rate to change its shape, depending on its own internal clock. By care - fully timing these changes, 3-D objects can be programmed to self-assemble. The research creates self-folding structures from 3-D printed patterns containing vary- ing amounts of different smart shape-memory polymers. The patterning, done with a 3-D printer, allows the resulting flat components to have varying temporal response to the same stimuli. Earlier methods required application of differential heating at specific locations in the flat structure to stimulate the shape changes. The research was reported September 8 in the journal Scientific Reports, which is published by nature Publishing. The work is funded by the u.S. air Force office of Scientific research, the u.S. national Science Foundation and the Singapore national research Foundation through the SuTD DmanD centre. 4-D Technology Allows Self- folding of Complex Objects