Programmable ultrasonic modulation of viscoelasticity in polymer-based elastomers: Experiments and constitutive...

Area of Science:

• Soft Matter Mechanics
• Polymer Science
• Materials Engineering

Background:

• Achieving reversible and programmable control of viscoelasticity in polymer elastomers at small strains is a significant challenge.
• Conventional methods often lack dynamic control and reversibility, limiting applications in precision engineering.

Purpose of the Study:

• To demonstrate ultrasonic vibration as a method for dynamic, reversible, and tunable modulation of viscoelasticity in polymer elastomers.
• To elucidate the molecular mechanisms underlying ultrasonic modulation of mechanical response.

Main Methods:

• Uniaxial compression experiments on polymer elastomers under ultrasonic vibration (19-22 kHz).
• Constitutive and inverse modeling using the Standard Linear Solid (SLS) model.
• Analysis of macroscopic mechanical changes and correlation with molecular dynamics.

Main Results:

• Ultrasonic vibration induces a reversible transition from viscoelastic to elastic-dominated behavior.
• Significant suppression of viscoelastic relaxation and energy dissipation observed.
• Tunable, reversible hardening achieved, with up to 20% increase in instantaneous elastic modulus and over 80% reduction in delayed modulus and viscosity.

Conclusions:

• Ultrasonic vibration offers a novel mechanism for precisely controlling polymer elastomer viscoelasticity.
• The findings provide practical insights for designing adaptive polymer systems for advanced applications.
• Potential applications include ultrasonic-assisted polishing, soft robotics, and flexible electronics.