Sliding Layer Helmet for Rotational Impact Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current helmets inadequately protect against oblique impacts, which can cause rotational injuries such as concussions, subdural haematomas, and diffuse axonal injuries due to insufficient absorption of rotational energy.
Innovation Solution
A helmet design featuring two sliding layers within an outer shell, where one or both layers are made of foam material, and a sliding facilitator comprising an organic polymer, polysiloxane, and surfactant, or a copolymer based on polysiloxane and organic polymer, to reduce friction and enhance energy dissipation during oblique impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional single-layer helmet design is used, then manufacturing is simple, but protection against oblique impacts is insufficient
Solution Approach 1:
The helmet is divided into multiple functional layers: an outer shell, a first energy-absorbing layer, a sliding layer, and a second energy-absorbing layer. Each layer serves a specific protective function, with the sliding layer specifically designed to reduce rotational energy transmission during oblique impacts. This segmentation allows the helmet to address multiple protection needs simultaneously while maintaining manageable complexity through modular design.
Solution Approach 2:
The helmet employs composite material construction with the sliding layer made from materials having a coefficient of friction between 0.05 and 0.3 relative to adjacent layers. This composite structure combines materials with different properties - the outer shell for impact resistance, energy-absorbing layers for crush protection, and the low-friction sliding layer for rotational energy dissipation - creating a synergistic protective system that exceeds the sum of individual components.
2Reliability
If sliding layers are added to reduce rotational energy transmission, then protection against rotational injuries improves, but manufacturing complexity increases
Solution Approach 1:
The key parameter controlling the sliding layer's function is its coefficient of friction, which is specified to be between 0.05 and 0.3. By precisely controlling this friction parameter through material selection and surface treatment, the helmet achieves optimal rotational energy reduction while maintaining manufacturability. This parameter-based approach allows for quality control through measurement and adjustment during the manufacturing process.
Solution Approach 2:
The sliding layer acts as an intermediary between the outer shell and the energy-absorbing layers. It mediates the transmission of forces by allowing controlled sliding during oblique impacts, converting some rotational energy into heat through friction while reducing the rotational impulse transmitted to the wearer's head. This intermediary function simplifies the overall design by providing a dedicated component for rotational energy management without requiring complex mechanisms in other layers.
3Loss of energy
If low friction material is used in sliding layer, then energy dissipation through sliding improves, but adhesion between layers may be reduced
Solution Approach 1:
The sliding layer exhibits local quality differentiation where its surface properties are optimized for low friction (coefficient between 0.05 and 0.3) to enable energy dissipation, while its bulk properties and bonding interfaces are designed for strong adhesion to adjacent layers. This local optimization allows the same component to simultaneously provide both low-friction sliding for energy dissipation and strong mechanical bonding for structural integrity, resolving the apparent contradiction between these opposing requirements.
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 sliding layers effectively reduce the transmission of rotational forces to the brain, minimizing the risk of rotational injuries by dissipating energy through friction and deformation, thereby improving protection against oblique impacts.
Implementation Method 1
the surface of one or both layers comprises a sliding facilitator to improve slidability between the two layers
Implementation Method 2
the sliding facilitator comprises (i) an organic polymer, a polysiloxane and a surfactant
Implementation Method 3
both of the two layers are made of foam material
Implementation Method 4
an energy absorbing layer called a liner
Data Source
Figure 1~3C
Figure 4~5
Figure 6
AI summary
The present invention provides a helmet comprising: two layers configured to slide with respect to each other; and wherein the surface of one or both layers comprises a sliding facilitator to improve slidability between the two layers, wherein the two layers configured to slide with respect to each other are each disposed within an outer shell of the helmet, and wherein the sliding facilitator comprises (i) an organic polymer, a polysiloxane and a surfactant; (ii) an organic polymer and a copolymer based on a polysiloxane and an organic polymer; or (iii) a non-elastomeric cross-linked polymer obtained or obtainable by subjecting a polysiloxane and an organic polymer to a cross-linking reaction.