TESORO ONE
Designed by NEUTRON HER
2020
NOTE: This project is a refresh of an older but very effective design solution I'd seen by other talented designers. The design helps to reduce plastic waste in manual toothbrushes.
The final form modelled after numerous thumbnail sketches.
Why design another toothbrush?
Did you know that over 1 billion plastic toothbrushes are thrown away in the US alone, creating 50 million pounds of waste annually?! And these toothbrushes will sit in our landfills an average of 400 years to finally decompose (usually if they're photodegradable) and eventually turn into microplastics that will eventually fill our oceans.
This was justification for me to dedicate some focus to a toothbrush design that may serve to remind us to be conscious of our everyday decisions that can collectively affect our planet.
"Good design is environmentally friendly" - Dieter Rams
In addition, I felt previous designs could be improved upon.
Tesoro, meaning 'treasure' in Italian
Called treasure to help elevate its perceived value to users. Everyday toothbrushes are often dull, boring tools; especially manual brushes. The ONE in its name indicates that it stands above the rest as the only toothbrush the user will need for quite some time.
Replace only the bristles, not the entire toothbrush
It's wasteful to replace an entire toothbrush after the recommended 3 months of use, especially when the toothbrush's plastic handle could have endured centuries of optimal use.
By having users only replace the bristles (typically the main limiting factor in a traditional manual toothbrush), more design emphasis and luxurious materials can be used in the construction of the toothbrush, making it more beautiful and appealing on the shelf. Paired with the growing societal awareness in sustainability, this enhances the likelihood of purchases.
Easy to clean
Short-comings immediately apparent in this design is the potential for moisture and bacteria to build up in the seam between the bristle body and the mounting bracket on the toothbrush head. To solve this, the bristle body is molded from food-safe FDA approved medium density closed cell silicone to easily pop in and out of the bracket from an applied narrow point pressure from behind for quick and easy cleaning.
Not to worry, during normal use, typical forces applied on the toothbrush make it unlikely for the bristle body to be inadvertently removed from its socket while brushing.
Pure and simple ergonomics
Knurled textured rubber overmolds are placed at effective locations on the TESORO ONE toothbrush for optimal comfort and accuracy while brushing. A non-cylindrical handle helps mount the toothbrush firmly in the users hand by preventing unintentional rotations of the brush.
Beauty at a glance
The packaging is designed with minimal marketing and branding distraction to reveal the innate beauty of the TESORO ONE at first glance. The smooth clear top housing is made of 100% recycled cast acrylic and is 100% recyclable. In addition, both the toothbrush's fitted bed and bottom half of the packaging housing are made of a highly compressed recycled paper pulp that achieves a smooth matt finish.
What's inside?
The TESORO ONE comes packaged with three replaceable bristle bodies. One of which is already conveniently installed in the toothbrush for immediate use.
FEA Analysis
A finite element analysis was conducted to simulate, test and validate the mechanical performance of the design. It is found that typical forces on the head of a toothbrush while brushing fluctuate between 0 - 3 Nm. By selecting a polyethylene material, we can produce a simple FEA .
The toothbrush handle is kept fixed, while forces are applied locally at the bristle head. I used 2 Nm as the force acting on the face of the bristle head, and 1 Nm as lateral forces. The lateral stresses will cancel each other out, leaving only for 2 Nm force acting on the head, thus justifying the simulated motion. We can see from this study that the design will function reasonably well, since we stay relatively green within the nominal forces.
(NOTE: the range of motion in the animation is exaggerated to help clarify the understanding of the stresses)
Because the lateral forces on the sides of the bristle head will likely never be acting at the same time, another study was done which isolated a single 1 Nm nominal force. We can see from this study as well, that the design will function reasonably well, since we stay relative green within the nominal force of 1 Nm.
Prototyping
Using 3D printing technology, a PLA model was created to tune and validate ergonomics in the hand.
Flexible and strong
A basic real-world stress test!
Thank You!
