Nanowire characterization is very important for optimizing the manufacturing process. You cannot improve, if you cannot properly measure something. Right now this process is not standardized, researchers select the “most suitable” portion of the nanowire collection, they measure the desired metric for arbitrary number of nanowires etc. That’s why nanomanufacturing process improvement results can be misleading.

I found an article about this topic: “A Statistics-Guided Approach to Precise Characterization of Nanowire Morphology” Article describes statistical methods for three metrics: length, density, diameter.

*Nanowire length*

They used three-dimensional geometric model to get a distribution of nanowire length (mean, variance). They measured projected lengths of nanowires for three different tilting angles.

*Nanowire density*

Nanowire density is usually defined to be the number of nanowires located per unit area. Method they propose: divide the substrate to n_{1} and also to n_{2} parts. Randomly pick n_{1} cells from n_{1}^{2} cells such that one region is selected from each row. Then from each chosen large cell, randomly pick one small cell inside the large cell to perform measurement. After this there is one more selection of cells such that there is one cell selected from each column.

*Nanowire diameter*

Using same logic as in length, they measure diameter projection for six different angles. For hexagonal nanowires, randomly measured tilt angles are between zero and 180/6 = 30

I will look for papers which cited this paper.