SL 2080 is a collaboration project that explores the concept of the self-lacing shoe.
The concept begins with a material called Nitnol, a shape memory alloy. When heated to a certain temperature, the wire returns to its original form and size prior to manipulation. It has a 3%-5% distortion rate.
During the initial conceptualization process, we tried to think about possible products to implement the Nitnol wire. Products ranged from tents, to shades, to blankets, and to protective gear.
The team decided to settle with "Smart Shoes" that are self-lacing. We have five primary reasons for this decision:
1. As we're entering the era of Smart Products, we believe that it is time for items as common as shoes to finally "start evolving."
2. We wanted to create a universal design for a new shoe "interface."
3. Individuals with dexterity issues can benefit from this product not only as a tool for easier shoe lacing, but also as a product they can have in common with other general consumers.
4. Combining the elements above, this new "Smart Shoe" could be a potential fashion statement/conversation starter.
5. As the trend of self-lacing shoes rises, new lines of self-lacing shoes will be introduced to the market.
Currently, there are self-lacing shoes that exist on the market. One of the primary examples of such a product would be the HyperAdapt, created by Nike. While such a concept is revolutionary, it does come with its own issues.
Since the product relies on batteries, LED lights, motors, and wired sensors, the HyperAdapt is bulkier than the typical footwear.
As the product continuously relies on battery power, the HyperAdapt also requires methods for charging; in this case, a smartphone-like-charger is used for the process. This means that having the convenience of a self-lacing shoe comes with the additional need of keeping the battery charged.
The HyperAdapt also has the issue with producing too much sound, as the motor kicks into high gear upon activation. This sounds very similar to motorized dispensers and equipment:
We began our experimentation process by looking at the possible tightening mechanisms that we could create using the Nitinol wire. The three primary connections we created are:
Wire Tightening In String
Wire Tightening Through Pulling Cloth (Slipper Band)
Wire Tightening Through Pulling String + Ratchet Locking Mechanism
With the idea settled on the ratchet mechanism, we continued working on iterations that improved the surface area and functionality of the locking mechanism.
We also did various studies on how the mechanism would be implemented as an interface of the shoe itself.
We slowly went from sketching to fully realizing the product in 3D. Below is a showcase of a looks-like model.
In the final product, the shoe is expected to function in through these orders of operations:
As the user wears the shoe, pressure is applied to the heel of the shoe sole, activating the pressure sensor. When the user presses/kicks the button at the back of the shoe, a trigger closes the circuit and the Nitinol wire heats up. During the heating process, the wire shrinks back to its original length, pulling on a ratchet mechanism. The ratchet mechanism pulls a strap, ultimately tightening the shoe. The wire cools off quickly after the user disengages the trigger. During the natural cycle of walking, the wire is stretched over time; however, the ratchet mechanism keeps the shoe tightened since it's locked in place--the user can loosen the shoe by simply pulling on the switch locking the ratchet mechanism.
The final product will utilize a new type of cloth battery. With this battery, the shoe sole will not be as bulky as Nike's HyperAdapt.
With small kinetic plates installed into the soles of the shoes, one can easily charge up the battery for another tightening activation in just 10 steps.
A works-like prototype is also created to demonstrate how the tightening mechanism functions. The video below demonstrates the strap tightening in real time:
Renders:
