Nanoaquarium: nanofluidic platform for in situ TEM imaging of fluid-mediated samples

Many nanoscale phenomena occur in liquid media, including nanoparticle and colloidal formation, nanowire liquid phase growth, electrochemical deposition and etching for batteries, and biological interactions. Real-time, in situ transmission electron microscope (TEM) imaging at nanoscale resolution would enhance the scientific understanding of these processes. Traditional TEM suffers from sample evaporation under high vacuum and requires very thin samples.

The Bau Lab has designed a device, termed the nanoaquarium, which allows for the concurrent flow of multiple sample streams for electron microscope imaging. This versatile flow cell will aid in studying dynamic nanoscale processes in fluids. 

The flow cell is sandwiched between two thin silicon nitride membranes using wafer-scale processing to enable mass production and hermetic sealing without polymers or glue for leak-free operation. Furthermore, there are on-chip integrated electrodes for sensing and actuation. The device (without flow control) was used to examine nanoparticle aggregation, bubble formation and growth, electrodeposition, crystallization, and patterning with electrons.

• Image processes in liquid media in real-time
• Integrated electrodes for actuation, sensing, electrochemical studies, temperature control
• On-chip storage of reagents
• Pneumatic pumping to improve control of liquid-based experiments
• Fully enclosed reservoir isolated from sample holder

• Study liquid samples with transmission electron microscopy
• Dynamic experiments including electrochemical deposition, electric field-induced self-assembly, reactions at liquid interfaces
• Biological interactions, protein conformational changes, nanoparticle migration, lipid membrane biophysics