Microscopic containers for sample archiving in environmental and biomedical sensors

This report describes our work on microfabricated containers that store small amounts of environmental samples for analysis. The containers are based on “strain architecture,” a fabrication technique which causes planar microstructures to fold out of plane from the substrate. These structures remain connected to electrodes for thermal actuation, electrochemical sample collection, and gas generation through electrolysis. Results are shown for collection of dissolved metals by electroplating using small voltages and currents that are compatible with the power resources of wireless sensor networks. Such containers will be useful for rapid in-situ analysis of concentrated samples, for maintaining a sample archive that can corroborate the results of an in-situ biochemical sensor, or for time-stamped collection of samples for offsite analysis using equipment that is unavailable in the field such as mass spectrometry or electron-beam based analysis methods.