Life Cycle Inventory Study of Biologically Inspired Self-Cleaning Surfaces

Abstract

In this paper, self-cleaning surfaces are investigated as an environmentally benign design option. These surfaces are a biologically inspired concept; first discovered on the lotus plant, micro- and nano-scale surface features aid in contaminant removal. Self-cleaning surfaces have been successfully recreated for engineering applications and appear on a variety of products. Because they can be cleaned with water alone, the use of such a surface could lead to less resource consumption during cleaning, if used in place of more resource intensive current industrial cleaning methods. A screening Life Cycle Inventory (LCI) study is used to determine if environmental benefits are obvious from the use of a self-cleaning surface over the entire life cycle. The study is performed on a chemical self-cleaning coating, selected for its durability, transparency and ease of use. The results of the LCI study are compared to current industrial cleaning practices of aqueous spray or ultrasonic cleaning, including solvent production and use of the cleaning machines. The LCI study reveals that environmental benefits are present in the use (cleaning) phase of a self-cleaning surface. However, when also considering the production of the self-cleaning surface, no clear environmentally superior choice exists. More analysis and evaluation of the production of self-cleaning surfaces is needed to select the more sustainable choice.

A Methodology for Identifying Environmentally Conscious Guidelines for Product Design

“…Secondly, finding and using analogies from nature is difficult, and environmental benefits are often assumed without being proven. Bras et al [11,12], for example, search for sustainable guidelines and principles by deducing them from the biosphere, but they have tested some bioinspired guidelines, such as self-cleaning surfaces [12], to find that they are not necessarily beneficial. Although studying nature may help define ecologically sustainable limits, it may not provide the best design analogies because of the manufacturing complexity in creating biomimetic systems.…”

“…Because of the shortcomings of these techniques, not all of the guidelines presented in the literature have been quantified or explored from a holistic lifecycle perspective. Designers should be aware of the potential for guidelines to improve one phase of a product's lifecycle while causing negative environmental repercussions in other phases of the lifecycle [12]. For example, a thermoelectric refrigerator might minimize the use of heavy components and harmful refrigerants relative to a vapor compression refrigerator, but vapor compression refrigerators tend to be more energy efficient.…”