Polyurethane Substrate Self-Adhesion via Selective Photo-Polymerization

Solution Overview

Problem

Polyurethane-based stretchable electronics lack sufficient adhesive properties for conformal contact with human skin, necessitating additional additives that complicate fabrication and limit biocompatibility.

Innovation Solution

A method of manufacturing self-adhesive polyurethane substrates using selective photo-polymerization, adjusting laser parameters to modify the crosslinked network, without additional additives, for use in biocompatible epidermal soft sensors and thermal heaters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If additional adhesive additives are added to polyurethane to improve adhesion, then adhesive properties are improved, but device complexity and fabrication difficulty increase

Engineering Contradiction:

Improveadhesive propertiesVSAvoidfabrication complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The polyurethane substrate performs self-adhesion through intrinsic adhesive properties generated by photo-polymerization, eliminating the need for external adhesive additives. The photo-polymerized regions create natural adhesion to skin through modified crosslinked network structure, allowing the material to serve its own adhesive function without additional components.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention changes the chemical structure parameters of polyurethane through selective photo-polymerization, transforming it from a non-adhesive material to a self-adhesive material. By controlling laser parameters (power, scanning speed, spacing) during photo-polymerization, the crosslinked network structure is modified to generate intrinsic adhesive properties while maintaining the base polyurethane composition without additional additives.

Inventive Principle:

Principle #35Parameter changes

2Strength

If adhesive additives are added to polyurethane to improve adhesion, then adhesive properties are improved, but biocompatibility is compromised

Engineering Contradiction:

Improveadhesive propertiesVSAvoidbiocompatibility

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The polyurethane substrate performs self-adhesion through intrinsic adhesive properties generated by photo-polymerization, eliminating the need for external adhesive additives. The photo-polymerized regions create natural adhesion to skin through modified crosslinked network structure, allowing the material to serve its own adhesive function without additional components.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention changes the chemical structure parameters of polyurethane through selective photo-polymerization, transforming it from a non-adhesive material to a self-adhesive material. By controlling laser parameters (power, scanning speed, spacing) during photo-polymerization, the crosslinked network structure is modified to generate intrinsic adhesive properties while maintaining the base polyurethane composition without additional additives.

Inventive Principle:

Principle #35Parameter changes

3Strength

If photo-polymerization is used to create self-adhesive polyurethane, then adhesive properties are improved without additives, but manufacturing precision requirements increase

Engineering Contradiction:

Improveadhesive propertiesVSAvoidlaser parameter control precision

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The invention changes the chemical structure parameters of polyurethane through selective photo-polymerization, transforming it from a non-adhesive material to a self-adhesive material. By controlling laser parameters (power, scanning speed, spacing) during photo-polymerization, the crosslinked network structure is modified to generate intrinsic adhesive properties while maintaining the base polyurethane composition without additional additives.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces mechanical mixing of adhesive additives with a photo-chemical process. Instead of mechanically combining multiple materials, the system uses laser-induced photo-polymerization to chemically modify the polyurethane structure, creating adhesive properties through chemical bond formation rather than physical mixing, thereby reducing manufacturing complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method produces self-adhesive polyurethane substrates with high adhesion and low Young's modulus, enabling effective conformal contact and biocompatibility for wearable devices like epidermal soft sensors and thermal heaters.

Implementation Method 1

performing selective photo-polymerization of the deposited polyurethane substrate with a laser device

Methodology Applied

Scientific EffectPhoto-polymerization: Photopolymerisation

Implementation Method 2

performing selective photo-polymerization of the deposited polyurethane substrate with a laser device

Methodology Applied

Scientific EffectLaser: Laser

Data Source

PatentUS12421433B2Method of manufacturing self-adhesive polyurethane substrates via selective photo-polymerization

Publication Date: 2025.09.23 KYUNGPOOK NAT UNIV IND ACADEMIC COOP FOUND

AI summary

Provided is a method of manufacturing self-adhesive polyurethanes using selective photo-polymerization. The method of manufacturing self-adhesive polyurethanes using photo-polymerization relates to a method for manufacturing photo-polymerized self-adhesive polyurethane substrates applicable to biocompatible epidermal soft sensors and attachable epidermal thermal heaters without particularly adding an adhesive additive.