Schematic diagram of a liquid cell with trapping nanochannel for TEM and STEM imaging of monometallic particles stuck in the nanochannels, where lattice fringe resolution in liquid is demonstrated. a) The suspended nanochannels with a controlled height of 100–170 nm, with trap regions ranging from 10-35 nm, are enclosed between two silicon nitride membranes. The nanochannels are filled with a liquid, which can be flowed in or exchanged using an external pump. The e^--beam goes through the membrane with the liquid and samples, thus allowing for imaging, spectroscopy, or diffraction measurements. b) HAADF-STEM image of trapped platinum particles in the nanochannels, with 1000 mbar of pressure applied. c) High magnification STEM image of particles in liquid stuck in the trapping region. d) Example of atomic scale resolution imaging of gold nucleation in solution from high electron beam intensity within a filled 60 nm high nanochannel, confined between two 10 nm Si₃N₄ membranes, captured on a 200 kV TEM. e) FFT of lattice fringe region in (d), showing peaks around 1.35 Å in the Fourier space.