Programmable Soft Robot Using DNA Hairpin Libraries for Shape Control

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Solution Overview

Problem

Current technologies lack addressable control over shape changes in materials without embedded wires, which limits the autonomy and specificity of chemomechanically responsive materials, as they rely on nonspecific stimuli like temperature, light, or pH for swelling or shrinking.

Innovation Solution

Development of a programmable gel using a library of biomolecules, specifically DNA sequences and hairpins, to achieve addressable control over swelling in hydrogels, allowing for precise shape changes by binding to crosslink nucleic acid sequences and adjusting the concentration of polymerizing and terminating hairpins to control the timing and degree of swelling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If wire-free stimuli (temperature, light, electromagnetic signals, pH) are used to control shape changes, then autonomy and miniaturization are improved, but addressable control and specificity are worsened

Engineering Contradiction:
ImproveautonomyVSAvoidaddressable control
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The gel is divided into multiple material domains, each containing specific crosslink nucleic acid sequences that can be independently controlled by complementary biomolecular stimuli, enabling addressable control of shape changes in different regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Nucleic acid sequences serve as intermediaries between the wire-free stimuli and the gel structure, providing specific recognition and binding sites that enable addressable control while maintaining the autonomy of wire-free operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If embedded wires are used to direct local mechanical deformations, then addressable control is improved, but physical bulk and device complexity are worsened

Engineering Contradiction:
Improveaddressable controlVSAvoidphysical bulk
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical wire-based control system with a chemical/biomolecular control system using nucleic acid sequences and their complementary stimuli, eliminating the need for physical wires and batteries while maintaining addressable control capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control mechanism transitions from mechanical parameters (wire placement, electrical signals) to chemical/biomolecular parameters (nucleic acid sequence composition, concentration ratios of polymerizing and terminating hairpins), enabling control without physical bulk

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If conventional chemicals are used for chemomechanical response, then versatility is improved, but specificity and addressable control are worsened

Engineering Contradiction:
ImproveversatilityVSAvoidspecificity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The gel is divided into multiple material domains, each containing specific crosslink nucleic acid sequences that can be independently controlled by complementary biomolecular stimuli, enabling addressable control of shape changes in different regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses nucleic acid sequence composition as a controllable parameter to achieve high specificity in biomolecular recognition and binding, enabling precise control over which domains respond to which stimuli

Inventive Principle:
Principle #35Parameter changes

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

Enables significant and controlled swelling or contraction of hydrogels in response to specific biomolecular stimuli, enabling complex shape changes and potential applications in metamorphic materials and soft robots without the need for wires or batteries.

Implementation Method 1

a first polymerizing hairpin capable of binding to the first crosslink nucleic acid sequence; a second polymerizing hairpin capable of binding to the second crosslink nucleic acid sequence

Methodology Applied
Scientific EffectDNA hybridization:

Implementation Method 2

Chemomechanically responsive materials present advantages in terms of autonomy, versatility, programmability, device integration and miniaturization

Methodology Applied
Scientific EffectChemomechanical response:

Data Source

PatentEP3676398B1A programmable soft robot
Publication Date: 2022.08.03 JOHNS HOPKINS UNIVERSITY
  • EP3676398B1 patent drawingFigure 1A~1C
  • EP3676398B1 patent drawingFigure 2A~2F
  • EP3676398B1 patent drawingFigure 3A~3C

AI summary

Described are a combinatorial library of DNA molecules that can induce shape changes within specific regions of hydrogels up to centimeter scales. The DNA molecules include polymerizing hairpins, terminating hairpins, reversal strands, and crosslink nucleic acid sequences.