Department of Materials Science & Engineering, University of Delaware, Newark, DE, USA.
Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA.
Soft Matter. 2021 May 19;17(19):5050-5060. doi: 10.1039/d1sm00451d.
The mechanical stimuli generated as a finger interrogates the physical and chemical features of an object form the basis of fine touch. Haptic devices, which are used to control touch, primarily focus on recreating physical features, but the chemical aspects of fine touch may be harnessed to create richer tactile interfaces and reveal fundamental aspects of tactile perception. To connect tactile perception with molecular structure, we systematically varied silane-derived monolayers deposited onto surfaces smoother than the limits of human perception. Through mechanical friction testing and cross-correlation analysis, we made predictions of which pairs of silanes might be distinguishable by humans. We predicted, and demonstrated, that humans can distinguish between two isosteric silanes which differ only by a single nitrogen-for-carbon substitution. The mechanism of tactile contrast originates from a difference in monolayer ordering, as quantified by the Hurst exponent, which was replicated in two alkylsilanes with a three-carbon difference in length. This approach may be generalizable to other materials and lead to new tactile sensations derived from materials chemistry.
当手指探测物体的物理和化学特征时产生的机械刺激构成了精细触觉的基础。用于控制触觉的触觉设备主要专注于再现物理特征，但精细触觉的化学方面可能被利用来创建更丰富的触觉界面并揭示触觉感知的基本方面。为了将触觉感知与分子结构联系起来，我们系统地改变了沉积在比人类感知极限更光滑表面上的硅烷衍生单层。通过机械摩擦测试和互相关分析，我们对哪些硅烷对可能可以被人类区分做出了预测。我们预测并证明，人类可以区分两种仅在一个氮取代碳的位置上不同的等电子硅烷。触觉对比的机制源自单层有序的差异，这可以通过赫斯特指数来量化，在长度相差三个碳原子的两种烷基硅烷中得到了复制。这种方法可能适用于其他材料，并导致从材料化学衍生的新的触觉感觉。
