Atomic force microscopy (AFM) was used to assess the indentation modulus Ms and pull-off force Fpo in four case studies of distinct evidence types, namely hair, questioned documents, fingerprints, and explosive particle-surface interactions. In the hair study, Ms decreased and Fpo increased after adding conditioner and bleach to the hair. For the questioned documents, Ms and Fpo of two inks were markedly different; ballpoint pen ink exhibited smaller variations relative to the mean value than printer ink. The fingerprint case study revealed that both maximum height and Fpo decreased over a three-day period. Finally, the study on explosive particle-surface interactions illustrated that two fabrics exhibited similar Ms, but different Fpo. Overall, it was found that AFM addresses needs in forensic science as defined by several federal agencies, in particular an improved ability to expand the information extracted from evidence and to quantify its evidentiary value.

中文翻译：

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用于纳米机械取证的定量扫描探针显微镜

原子力显微镜 (AFM) 用于评估四个不同证据类型的案例研究中的压痕模量 Ms 和拉拔力 Fpo，即头发、可疑文件、指纹和爆炸性粒子表面相互作用。在头发研究中，在头发上添加护发素和漂白剂后，Ms 减少，Fpo 增加。对于被质疑的文件，两种墨水的Ms和Fpo明显不同；与打印机墨水相比，圆珠笔墨水相对于平均值的变化更小。指纹案例研究表明，最大高度和 Fpo 在三天内都下降了。最后，对爆炸粒子-表面相互作用的研究表明，两种织物表现出相似的 Ms，但不同的 Fpo。总的来说，发现 AFM 满足了几个联邦机构定义的法医学需求，