Inverted Scanning Microwave Microscopy of a Vital Mitochondrion in Liquid

The inverted scanning microwave microscope (iSMM) is a recently developed variety of scanning microprobe microscopes. Similar to an SMM, the iSMM is sensitive to not only surface structure, but also electromagnetic properties below the surface. Different from the SMM, the iSMM can be converted from any scanning probe microscope, such as an atomic force microscope (AFM) and a scanning tunneling microscope, with a simple metal probe to outperform the SMM in terms of ruggedness, bandwidth, sensitivity, and dynamic range. This paper reports the first iSMM images of a vital mitochondrion in an isotonic glucose solution. Compared to the AFM and SMM, the iSMM offers more insights into the mitochondrion. This shows the potential of iSMM for noninvasive and label-free imaging and characterization of subcellular structures.