APPLICATIONS OF TECHNOLOGY:
Transmission Electron Microscopy for
- Reactions can be observed at atomic resolution
- Versatile micro/nanofluidic setup can be used to study either biological samples or nanomaterials in liquids
- Ability to mix two or more solutions and observe changes at atomic resolution
- Can be mass produced
A Berkeley Lab research team including Paul Alivisatos and Alex Zettl has developed an Atomic-Resolution Transmission Electron Microscope (TEM) Cell for Use with Liquid Samples to observe chemical reactions, at any stage, of biological and nanomaterial samples in solution. To improve upon the limited resolution of commercially available TEM sample holders, the Berkeley Lab researchers integrated imaging windows or view ports made of atomically thin graphene along multiple sites of the reaction microchannels. When an electron beam passes through the graphene view port, an atom-resolution image of the liquid sample can be produced.
The researchers are the first to use a new fabrication technique to form graphene view ports on the substrate of the microchannels. Unlike conventional approaches, the new technique prevents leakages in the ultrahigh vacuum of a TEM, as the microfluidics can be sealed in the TEM cell without bonding two separate membranes.
The invention’s fabrication process can control the size of the microchannels formed. The graphene view ports can also be integrated with micro/nanofluidics to deliver several liquid samples at once to a TEM sample holder in an ultrahigh vacuum.
The Berkeley Lab TEM Cells’ versatility allows for the in situ analysis of nanomaterials or biological samples in liquid without using conventional cryo techniques. Micro/nano-electrodes can also be used to electrically stimulate the samples, and the temperature of the samples can be controlled in situ.
Although TEMs are important tools for the development of advanced materials and pharmaceuticals, some commercially available sample holders lack the high-resolution required to accurately image liquid nanomaterials, or the in situ reactions of biomolecules or nanoparticles with each other in solution, at the atomic level due to the thickness of the membrane walls that hold the liquid. In other words, the thickness of the microchannel walls that allow the fluid to flow in the TEM poses a limit to the imaging resolution of these devices. This new Berkeley Lab TEM technology overcomes these limitations.
DEVELOPMENT STAGE: Proven principle
STATUS: Patent pending. Available for licensing or collaborative research.
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REFERENCE NUMBER: 2013-011 / IB-3332