TABLE OF CONTENTS

• THE BASIS
• DESIGN CONSIDERATIONS – BORN NOT BUILT
• PARAMETRIC MODELING
• BEYOND PROTOTYPING
• SAFETY ENGINEERING
• TESTING STANDARDS
• PATENTED SAFETY TECHNOLOGIES
• COMPOSITE MATERIAL PROPERTIES
• IMPACT SIMULATION
• HELMET VARIANTS
  • ARMADILLO
  • HERCULES
  • ATHENA
• CHIN STRAP AND LANYARD INCLUSION
• DETECT-PROTECT

THE BASIS

As part of our projects in the micro-mobility space, a helmet that would neatly fold into a form factor that could be easily carried around will be our first product to establish this new sense of freedom and mobility after having been constrained in movement due to the COVID pandemic. The foldability aspect of the helmet would facilitate:

• Shipment – You can ship more helmets in the same volume.
• Warehouse storage space – Your storage space is reduced
• Usability aspect – You can easily fold the helmet to make it less clunky for carrying it around.

The prime directive of this project is to achieve the minimal optimized shape goals of foldability that adhere to compliance requirements. Parametric modeling is a theme that runs across the spine of this project. Additionally, being customizable and 3D printed using Additive Manufacturing technologies will mitigate supply chain issues and make it more customer centric in function.

To account for the functionality – the should conditions that are the basis for the folding helmet, we have created a manifesto that details the needs for our design and engineering teams.

DESIGN CONSIDERATIONS – BORN NOT BUILT

In this project we utilize the tenets in CAD, CAE and Additive Manufacturing – Parametric Modeling, Simulations, Generative Design, 3D-printing, purposeful use of Materials and Design for Manufacturability accomplish what we term “Born not Built”.

1.  FORM FITTING TO HEAD SHAPES

We will use anthropometric data gathered during the 2003 NIOSH survey, parameters for new head-forms in five size categories were developed by the National Personal Protective Technology Laboratory (NPPTL) of NIOSH.

Shown below are three-dimensional (3D) scans of five individuals, who most closely represented a given size category were averaged together.

The resulting models include facial features not found on current standard head-forms. Five distinct sizes (small, medium, large, long/narrow, and short/wide) of digital 3D head-forms have been created to account for the overall size and shape of the face. The NIOSH head-forms are symmetric and represent the facial size and shape distribution of current U.S. respirator users.

Shown above is the baseplate that can morph into any head form procured by scanning. The 42 control points indicated by the black dots define the extents of the shape of the head and its articulation for the folding movement:

• transverse – top-down along the z-axis,
• saggitarial – left-right along the y-axis,
• coronal – rotation along the y-axis about an offset pivot point,
• rotational – rotation along the vertical z-axis.

These will be the four variants of the design of the folding pattern for the helmet.

Represented below is how the control points project to the extremities of the headform (head/skull cap) and morphs to fit the different standardized shapes:

PARAMETERIC FIT TEST TO THE DIFFERENT HEADFORMS

2. DESIGN VARIANTS

The diagram below illustrates the different folding considerations for the design of the folding helmet each of which was CADed with appropriate living hinges to enable print in place mechanisms to enable the retractions.

3. CONFORMING DESIGN PATTERN

4. PRODUCT MANAGEMENT
5. 3D PRINT TESTING

To test the design, we have printed it on a variety of 3D printers – ANYCUBIC, CREALITY 3D Printers, @Prussa, @Dremel, LulzBot, Stratasys, and will be doing it on industrial grade printers like Markforged, Desktop Metal and other AM technologies.

PARAMETRIC MODELING

Based on the headform views shown above, a customized template will be created to represent the shape for the helmet. This will be called the sliver that will be used to generate the slice that holds all the slats of the articulating helmet. The number of slats will define the height of the helmet when folded corresponding to a definite angle. This is represented in the diagram below:

KIRIGAMI: Outcome based modeling – From sliver to slice to slats

The animation below shows the concept for the parametric modeling for the Armadillo slats:

Here are the steps to model the folding helmet

1. Import headform
2. Import baseplate
3. Transform baseplate to match with the base of the helmet that would fit the headform
4. Define the frontal extent (blue)
5. Define the rear extent (red)
6. Pivot the rear extent 180 degrees
7. Create sliver.
8. Create slice Extrude sliver based on the pivot axis to coform with the number of slats (6). Have a formula to create slice based on number of slats. If 1 then it is a hard hat with the sliver defining the brim
9. Divide slice into the number of slats by including tolerances.
10. Create appropriate grooves and stubs to enable the motion.
11. Add brim that corresponds to the sliver.
12. Open the helmet slats to test.
13. Project the control points onto the surface of the helmet (red) and the headform (blue) to check for gaps.

Infilling to strengthen the shell structure

BEYOND PROTOTYPING

Beyond this prototype stage, we plan to have variants for hard hats, industrial use, the military, bicycle helmets and other uses that would comply with all the regulations and standards and be tested for strength and durability utilizing tools from Hexagon Manufacturing Intelligence (NASTRAN, ADAMS, DIGIMAT, etc.) and looking at advances in Materials technology (ICME and real testing).

SAFETY ENGINEERING

Helmets are designed to protect the head from impact and injury. In order to ensure that a helmet provides adequate protection, engineers must have a solid understanding of the cranial structure of the human skull.

The human skull is made up of several different bones that are joined together by sutures. These bones include the frontal bone, the parietal bones, the temporal bones, the occipital bone, and the sphenoid bone. The skull also contains several openings, such as the foramen magnum (which allows the spinal cord to pass through), the optic canal (which allows the optic nerve to pass through), and the jugular foramen (which allows the jugular vein and other nerves to pass through).

The shape and structure of the skull plays a key role in determining how a helmet should be designed. For example, the curvature of the skull affects the way that impact forces are transmitted through the skull during an impact. In addition, the location and size of the openings in the skull can affect how well a helmet protects the head in the event of an impact.

Engineers who design helmets must take all of these factors into account when designing their products. They must also consider other factors, such as the weight and shape of the helmet, the materials it is made from, and the way that it is secured to the head. By carefully considering all of these factors, engineers can design helmets that provide maximum protection for the head while also being comfortable and practical to wear.

The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join. It is located on the side of the skull, just behind the temple. The pterion is known as the weakest part of the skull. The anterior division of the middle meningeal artery runs underneath the pterion. Consequently, a traumatic blow to the pterion may rupture the middle meningeal artery causing an epidural hematoma. The pterion may also be fractured indirectly by blows to the top or back of the head that place sufficient force on the skull to fracture the pterion.

The pterion receives its name from the Greek root pteron, meaning wing. In Greek mythology, Hermes, messenger of the gods, was enabled to fly by winged sandals, and wings on his head, which were attached at the pterion.

Based on the above and our understanding of safety conditions and the regulations therein, here is what we at Numorpho are doing to engineer our helmets.

When designing a helmet to protect sensitive areas of the skull such as the pterion, engineers must consider several safety structures to ensure maximum protection. The pterion is a small, delicate area on the side of the skull where several bones come together, including the temporal bone, the parietal bone, the frontal bone, and the sphenoid bone. It is an area of the skull that is particularly vulnerable to impact and injury.

Here are some safety structures that engineers should keep in mind when designing a helmet to protect the pterion:

1. Padding: The helmet should be lined with high-density foam padding that can absorb impact energy and distribute it across a wider area of the skull. This can help to reduce the force of an impact on the pterion.
2. Reinforcement: The area of the helmet that covers the pterion should be reinforced with additional layers of material. This can help to further reduce the force of an impact on the pterion.
3. Shell shape: The shape of the helmet shell should be designed to minimize the risk of direct impact to the pterion. This can be achieved by creating a helmet shell that covers a larger area of the skull, or by incorporating a raised ridge or bump over the pterion that can deflect impact forces away from this area.
4. Impact testing: Helmets should be rigorously tested to ensure that they can effectively protect the pterion from impact. This testing should involve simulating different types of impact forces and measuring the forces that are transmitted to the skull.

By considering these safety structures, engineers can design helmets that provide effective protection for the sensitive areas of the skull like the pterion.

Here is an excellent resource on designing helmets for safety:

https://www.mdpi.com/1424-8220/20/21/6241

TESTING STANDARDS

When designing helmets, there are several standards that must be adhered to in order to ensure that the helmet provides adequate protection. These standards are set by various organizations and regulatory bodies, and they are designed to ensure that helmets meet minimum safety requirements.

Here are some of the standards that must be adhered to when designing helmets:

1. Impact protection: Helmets must be designed to provide adequate impact protection. This includes designing the helmet to absorb and distribute impact forces across a wider area of the skull, and ensuring that the helmet does not come off during impact.
2. Penetration resistance: Helmets must be designed to resist penetration from sharp objects. This includes designing the helmet shell and liner to prevent sharp objects from penetrating through to the skull.
3. Retention system: Helmets must be designed with a retention system (such as a chin strap) that is strong enough to keep the helmet securely on the head during impact.
4. Field of vision: Helmets must be designed to provide an adequate field of vision for the wearer. This includes designing the helmet to not obstruct the wearer’s view, and ensuring that the visor or face shield does not distort the wearer’s vision.
5. Durability: Helmets must be designed to withstand normal wear and tear, as well as impacts and other stresses that the helmet may be subjected to during use.

These standards are set by organizations such as the Consumer Product Safety Commission (CPSC) in the United States, the European Committee for Standardization (CEN) in Europe, and the Snell Memorial Foundation. Compliance with these standards is typically indicated by a certification label or mark on the helmet.

Helmets are tested to make sure that they meet:

• Peripheral Vision Test – they do not block the riders vision,
• Positional Stability Test – they do not come off when the rider falls,
• Retention Strength Test – the straps that hold a helmet on a rider’s head do not stretch enough to let the helmet come off in an accident, and
• Impact Attentuation Test – the helmet significantly reduces the force to the rider’s head when the helmet hits a hard surface.

Testing Compliance Information

https://www.cpsc.gov/Business–Manufacturing/Business-Education/Business-Guidance/Bicycle-Helmets

https://www.cdc.gov/niosh/npptl/topics/respirators/headforms/default.html

https://www.cdc.gov/niosh/data/datasets/rd-10130-2020-0/default.html

https://helmets.org/standard.htm

Click to access 077182.pdf

PATENTED SAFETY TECHNOLOGIES

MIPS https://mipsprotection.com/

WAVECEL https://wavecel.com/

KAVSPORTS   https://kavsports.com/

COMPOSITE MATERIAL PROPERTIES

Here are the specifications for the different materials

Markforged

Shell material

• Onyx (Slats A, B and C)
• Onyx FR (Flame resistant)
• Onyx ESD (Stronger, stiffer and ESD resistant)

Reinforced Infill Material

• None (Slats A, B and C)
• Carbon Fiber Infill (Slat C)
• Carbon Fiber FR Infill
• Kevlar Infill (Slat C)
• HSHT Fiberglass Infill
• Fiberglass Infill (SlatC)

IMPACT SIMULATION

HELMET VARIANTS

The following are the different helmet projects based on the type of articulation/folding mechanism:

Variant	Helmet Type	Description
Armadillo	Hoodie	Rotary motion along the y-axis. Appropriate for bump caps, hard hats, industrial and construction use, military and health apps.
Hercules(named after the MORPHO butterfly species)	Hoodie	Tootsie-roll based rotary motion along the x-axis. Variation of the Armadillo turned by 90 degrees and having bi-directional motion around the center line. Hercules is a species of the Blue Morpho butterfly. This version of the helmet will enable the embedding of the Arduino Nicla Vision and Sense ME sensors to enable safety in industrial and home use.
Athena(named after the MORPHO butterfly species)	Hoodie	This will be orthogonal to the Hercules model and correspond with the Aramadillo in shape with the largest slat on the top and a bi-fold from the front and the back.
Chelsea	Pita	Horizontal movement along the y-axis. Appropriate for bicycle helmets that need padding.
xx	Rotor	Rotary motion along the z-axis.
xx	Roti	Vertical motion along the z-axis.

CHIN STRAP AND LANYARD INCLUSION

A chin strap has a design function that secures the head and helmet in order to prevent it from rolling off.

DETECT-PROTECT

To enable safe operations and personal safety, we are embedding sensors into the helmet to enable users to be aware of their surroundings, correspond with services (utilizing IoT gateways and other wireless protocols).

Overall, embedding electronic boards into our folding helmet. By carefully selecting and integrating electronic componentry, we can create a helmet that is not only safe and comfortable but also provides advanced sensing and voice-based functionality.

Embedding sensors into a helmet to enable users to be aware of their surroundings and correspond with services is a great way to enhance personal safety and improve overall operations. Here are some potential considerations for selecting and integrating sensors into the helmet:

1. Sensor selection: Depending on the specific use case, you’ll need to select sensors that are suitable for the environment and provide the necessary data to achieve the desired functionality. For example, if the goal is to detect obstacles or hazards, you might need to include proximity sensors or cameras. If the goal is to monitor the user’s vital signs, you might need to include biometric sensors such as heart rate monitors or blood pressure sensors.
2. Communication protocols: The sensors will need to communicate with each other and with external services to provide the necessary data. You’ll need to select communication protocols that are reliable, secure, and suitable for the use case. For example, Wi-Fi, Bluetooth Low Energy (BLE), or Zigbee could be good options.
3. Power: The sensors will require a power source to function. You’ll need to select a power source that is small, lightweight, and provides enough power for the required sensors. For example, a small lithium-ion battery could be suitable.
4. Data processing: The data collected by the sensors will need to be processed to provide actionable information. You’ll need to select a processor that is powerful enough to handle the required tasks, but also low-power to conserve battery life. For example, an ARM Cortex-M processor could be a good option.
5. IoT gateways: To correspond with external services, you’ll need to connect the sensors to an IoT gateway. The IoT gateway will act as a bridge between the sensors and external services, and will need to support the required communication protocols.

Overall, embedding sensors into a helmet is a challenging but exciting use case. By carefully selecting and integrating sensors, communication protocols, power sources, data processing, and IoT gateways, you can create a helmet that provides advanced sensing and communication functionality to enhance personal safety and improve operations.