Biofidelic Conductive Skin Simulant Using Siloxane Network
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current skin simulants fail to accurately mimic the non-linear hyperelastic properties of human skin, and existing conductive polymers do not effectively simulate human tissue behavior while also being conductive, posing challenges in biomechanical testing and surgical training, particularly for vaginal tissue and ballistic munitions development.
Innovation Solution
Development of biofidelic conductive skin simulants using crosslinked siloxane polymers with conductive fibers, which exhibit non-linear viscoelastic properties similar to natural skin, allowing for precise simulation of human skin mechanics and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional skin simulants (gelatin-polyurethane, synthetic chamois) are used, then basic structural properties are achieved, but they fail to accurately mimic the non-linear hyperelastic properties of human skin
Solution Approach 1:
The patent employs a multi-layer composite structure consisting of a polymeric substrate layer and a skin-like outer layer. The outer layer is formulated with specific polymer blends and plasticizers to achieve non-linear hyperelastic properties that closely match human skin. This composite approach allows each layer to contribute specific properties, with the outer layer providing the critical hyperelastic behavior while the substrate provides structural support.
Solution Approach 2:
The patent systematically adjusts compositional parameters including polymer molecular weight, plasticizer concentration, crosslinking density, and filler content to tune the mechanical properties. By varying these parameters, the formulation achieves the characteristic non-linear stress-strain behavior of human skin, including the toe region, linear region, and failure point that match in-vivo skin response.
2Reliability
If conductive fillers (metal powders, carbon) are added to polymer matrices, then electrical conductivity is achieved, but high volume fractions are required leading to inhomogeneity and loss of processability
Solution Approach 1:
The patent introduces a surface-modified conductive filler that acts as an intermediary between the polymer matrix and the conductive network. The filler undergoes surface treatment with silanes or other coupling agents that improve dispersion and reduce agglomeration. This allows achieving percolation threshold at lower volume fractions while maintaining homogeneous distribution and processability of the composite material.
Solution Approach 2:
The conductive filler is strategically distributed within the multi-layer structure, with higher concentrations in the skin-like outer layer where conductivity is most needed for sensing applications. The substrate layer contains lower filler concentrations, optimizing the overall balance between conductivity, mechanical properties, and processability of the composite system.
3Ease of manufacture
If a single homogeneous skin simulant material is used, then ease of manufacture is improved, but it cannot account for the non-uniform properties of skin across different body locations and individuals
Solution Approach 1:
The patent divides the skin simulant into multiple functional layers with distinct compositions and properties. The polymeric substrate layer provides structural support with different mechanical properties than the skin-like outer layer, which is formulated to match epidermal-dermal tissue characteristics. This segmentation allows each layer to be optimized independently while accounting for the gradient of properties found in real skin from deeper to superficial layers.
Solution Approach 2:
Different regions of the skin simulant can be formulated with locally optimized properties to represent specific body locations. The multi-layer structure allows variation in thickness, composition, and mechanical properties across different areas of the simulant, enabling it to mimic the non-uniform characteristics of human skin at different anatomical sites while maintaining overall manufacturability.
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 biofidelic conductive skin simulants effectively mimic the mechanical properties of human skin, including vaginal tissue, enabling improved biomechanical testing and surgical training, while maintaining conductivity, thus addressing the limitations of existing skin simulants and conductive polymers.
Implementation Method 1
Skin is a viscoelastic material and exhibits non-linear strain behavior
Implementation Method 2
a skin simulant having the realistic non-linear hyperelastic properties of the human skin
Implementation Method 3
Conductive polymer composites have been prepared in different forms... to advance research and testing of wearable technologies and for acquisition of biomechanical information from the human body
Data Source
AI summary
Described are biofidelic conductive skin simulants closely mimicking the biomechanical properties of natural human skin, including vaginal skin tissue. The conductive simulant contains a siloxane network and conductive fibers.