Metal–organic biohybrids (MOBs) are a family of materials containing a metal component, such as copper, and a biological component, such as the amino acid dimer cystine.  One of the MOB families first described was the copper-high aspect ratio structure called CuHARS.  Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of CuHARS revealed linear morphology and smooth surface texture. SEM, TEM and light microscopy showed that CuHARS composites had scalable dimensions from nano- to micro-, with diameters as low as 40 nm, lengths exceeding 150 microns, and average aspect ratios of 100.