@article{bachmann_hanrahan_dickey_lazarus_2022, title={Self-Folding PCB Kirigami: Rapid Prototyping of 3D Electronics via Laser Cutting and Forming}, volume={14}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.2c01027}, DOI={10.1021/acsami.2c01027}, abstractNote={This paper demonstrates laser forming, localized heating with a laser to induce plastic deformation, can self-fold 2D printed circuit boards (PCBs) into 3D structures with electronic function. There are many methods for self-folding but few are compatible with electronic materials. We use a low-cost commercial laser writer to both cut and fold a commercial flexible PCB. Laser settings are tuned to select between cutting and folding with higher power resulting in cutting and lower power resulting in localized heating for folding into 3D shapes. Since the thin copper traces used in commercial PCBs are highly reflective and difficult to directly fold, two approaches are explored for enabling folding: plating with a nickel/gold coating or using a single, high-power laser exposure to oxidize the surface and improve laser absorption. We characterized the physical effect of the exposure on the sample as well as the fold angle as a function of laser passes and demonstrate the ability to lift weights comparable with circuit packages and passive components. This technique can form complex, multifold structures with integrated electronics; as a demonstrator, we fold a commercial board with a common timing circuit. Laser forming to add a third dimension to printed circuit boards is an important technology to enable the rapid prototyping of complex 3D electronics.}, number={12}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Bachmann, Adam L. and Hanrahan, Brendan and Dickey, Michael D. and Lazarus, Nathan}, year={2022}, month={Mar}, pages={14774–14782} }
 @article{ma_bharambe_persson_bachmann_joshipura_kim_oh_patrick_adams_dickey_2021, title={Metallophobic Coatings to Enable Shape Reconfigurable Liquid Metal Inside 3D Printed Plastics}, volume={13}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.0c17283}, DOI={10.1021/acsami.0c17283}, abstractNote={Liquid metals adhere to most surfaces despite their high surface tension due to the presence of a native gallium oxide layer. The ability to change the shape of functional fluids within a three-dimensional (3D) printed part with respect to time is a type of four-dimensional printing, yet surface adhesion limits the ability to pump liquid metals in and out of cavities and channels without leaving residue. Rough surfaces prevent adhesion, but most methods to roughen surfaces are difficult or impossible to apply on the interior of parts. Here, we show that silica particles suspended in an appropriate solvent can be injected inside cavities to coat the walls. This technique creates a transparent, nanoscopically rough (10-100 nm scale) coating that prevents adhesion of liquid metals on various 3D printed plastics and commercial polymers. Liquid metals roll and even bounce off treated surfaces (the latter occurs even when dropped from heights as high as 70 cm). Moreover, the coating can be removed locally by laser ablation to create selective wetting regions for metal patterning on the exterior of plastics. To demonstrate the utility of the coating, liquid metals were dynamically actuated inside a 3D printed channel or chamber without pinning the oxide, thereby demonstrating electrical circuits that can be reconfigured repeatably.}, number={11}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Ma, Jinwoo and Bharambe, Vivek T. and Persson, Karl A. and Bachmann, Adam L. and Joshipura, Ishan D. and Kim, Jongbeom and Oh, Kyu Hwan and Patrick, Jason F. and Adams, Jacob J. and Dickey, Michael D.}, year={2021}, month={Mar}, pages={12709–12718} }
 @article{eneh_bolen_suarez-martinez_bachmann_zimudzi_hickner_batys_sammalkorpi_lutkenhaus_2020, title={Fourier transform infrared spectroscopy investigation of water microenvironments in polyelectrolyte multilayers at varying temperatures}, volume={16}, ISSN={["1744-6848"]}, DOI={10.1039/c9sm02478f}, abstractNote={Tightly and loosely bound water molecules within polyelectrolyte multilayers are examined as a function of temperature and salt.}, number={9}, journal={SOFT MATTER}, author={Eneh, Chikaodinaka I. I. and Bolen, Matthew J. J. and Suarez-Martinez, Pilar C. C. and Bachmann, Adam L. L. and Zimudzi, Tawanda J. J. and Hickner, Michael A. A. and Batys, Piotr and Sammalkorpi, Maria and Lutkenhaus, Jodie L. L.}, year={2020}, month={Mar}, pages={2291–2300} }