Issue link: https://iconnect007.uberflip.com/i/634491
48 SMT Magazine • February 2016 er processes common in that era. While less was more 23 years ago, even less is even more today. During 2015, Aqueous Technologies' prod- ucts saved millions of gallons of water (a fact not lost on our West Coast customers). More of our zero discharge cleaning systems were sold than any other year resulting in the savings of millions of gallons of water consumed and the complete elimination of a need for a drain. Our goal in 2016 is to continue our environmental stewardship by providing more zero discharge models to companies who clean their assem- blies, resulting in improved product reliability and a cleaner, greener planet. SMT Lawrence Livermore National Laboratory re- searchers have created a library of nanoporous gold (np-Au) structures on a single chip that has direct applications for high-capacity lithium ion batteries as well as neural interfaces. np-Au is produced through an alloy corro- sion process known as dealloying that generates a characteristic three-dimensional nanoscale net- work of pores and ligaments. llNl researchers and their university of cali- fornia, Davis collaborators describe a method for creating a library of varying np-Au morphologies on a single chip via precise delivery of tunable la- ser energy. uc Davis professor Erkin Seker served as the principal investigator of the uc Fees proj- ect that primarily funded the work, along with co-pi Monika biener of llNl's Materials Science Division. "Traditional heat application techniques for the modification of np-Au are bulk processes that can- not be used to generate a library of different pore sizes on a single chip," said LLNL staff scientist Ibo Matthews, co-author of the paper. "Laser mi- croprocessing offers an attractive solution to this problem by providing a means to apply energy with high spatial and temporal resolution." The researchers used multiphysics simulations to predict the effects of continuous wave vs. pulsed laser mode and varying thermal con- ductivity of the sup- porting substrate on the local np-Au film temperatures during photothermal anneal- ing. They were then able to fabricate an on-chip material library consisting of 81 np-Au samples of nine different morphologies for use in the parallel study of structure–property relationships. "These libraries have the potential to drastically increase the throughput of morphology interac- tion studies for np-Au, specifically in applications such as high capacity lithium ion batteries, cell- material interaction studies for neural interfaces, analytical biosensors, as well as nanoscale mate- rial science studies," said Biener, co-author of the paper. This work sets the foundation for understanding laser-based annealing of porous thin film materials. The fabrication of single chip material libraries has the potential to increase the throughput of mate- rial interaction testing in many disciplines through easy single-chip material screening libraries. llNl's Juergen biener of the Material Sciences Division collaborated on the work along with uc Davis researchers Christopher Chapman (lead au- thor) and ling Wang. Researchers Go for the Gold on a Single Chip Mike Konrad is the president of Aqueous Technologies. He is also a member of the SMT Magazine Editorial Advisory Board. greeNer cleaNiNg