CAREER: Interfacial Fracture, Fatigue, and Switchable Adhesion of Soft Sticky Adhesives

This Faculty Early Career Development (CAREER) project will support research that investigates novel design strategies to enhance the adhesion and switching performance of soft sticky adhesives. These materials are made of rubbery viscoelastic polymer networks that form strong adhesion to various materials within seconds under gentle pressure through dense physical bonds at the interface.

Their broad applications range from conventional load bearing tapes to novel adhesives for wound dressing, wearable sensors, and flexible displays. Their expanding application domain has revealed a critical need for enhanced fatigue resistance under prolonged cyclic loads, together with a new opportunity for controlled switching between adhering and non-adhering states.

This award will support fundamental research to understand the mechanics of interfacial fracture, fatigue, and switchable adhesion in soft sticky adhesives through an integrated experimental and modeling approach. The outcome of the research will benefit the economy and society by enabling advanced fatigue-resistant and switchable soft sticky adhesives for load bearing, electronics, manufacturing, robotics, and healthcare applications.

The research-integrated education will provide high school, undergraduate, and graduate students with multifaceted experiential learning through joint academia-industry workshops, summer camps, and curriculum enhancement.

The objective of this CAREER project is to understand and harness the interplay between interfacial bonding, bulk dissipation, stimuli-responsiveness, and interfacial geometry (e.g., surface patterning) in soft sticky adhesives. To achieve this objective, model material systems will be fabricated and characterized to understand the underlying mechanisms.

The investigation will focus on interfacial fracture, fatigue, and associated dissipation at multiple length scales by experimentally measuring key material properties, advancing theoretical models, and performing finite element simulations. In addition, a new switchable soft sticky adhesive based on thermally actuated liquid crystal elastomers (LCEs) will be designed by tuning the reversible phase transformation and viscoelastic dissipation in the material.

Finally, the research will leverage the interaction between material properties and surface patterning to improve the adhesion and switching performance.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.