Polymer research demonstrates pressure sensitive adhesives with tunable adhesion properties

Pressure sensitive adhesives (PSAs) are ubiquitous in our daily life in products such as sticky notes and adhesive bandages. In spite of their widespread use, there are properties of such PSAs that need improvement. On-demand tailoring of adhesive strength and the ability to stick to wet and underwater surfaces are two such unmet features. Repositionable sensors on wet and underwater environments and adhesive bandages for fragile skin are two applications that can benefit from improvements in PSA design.

The polyurethane used in this study and the images of quartz plates after removing the adhesive tapes (top). The peel strengths of each sample with predetermined irradiation time (bottom).

Recent work by Yen-Ming Tseng, Amal Narayanan, Kaushik Mishra, Xinhao Liu and Abraham Joy, that was published in ACS Applied Materials & Interfaces, “Light-Activated Adhesion and Debonding of Underwater Pressure-Sensitive Adhesives”, has demonstrated an adhesive with tunable adhesion properties. The adhesion strength increases within seconds of UV exposure and further UV irradiation significantly decreases the adhesion strength, thereby enabling its easy removal. Furthermore, this tunable adhesive was also capable of bonding the substrate underwater and demonstrated the same trends of adhesion strengths as observed in the dry condition.

The polyurethane tape adhered strongly when brought in contact with the substrate underwater.