Pressoles

 

Project Title

Pressoles – Pressure sensitive soles

 

Project Description

This project was a part and in continuation of the series of projects I made for the previous assignments. Keeping in mind the theme I had selected earlier, I decided to go ahead with it. I was planning on building something that is meant for a bold user who likes to live life to the fullest. The idea behind this wearable was to create something that made the wearer stand out in the crowd. This project was meant to add a fun and interesting element to a simple activity such as walking, dancing or running and make it enjoyable for the audience as well. This starting point led me to come up with the idea of pressure sensitive soles that display your pressure interaction in terms of illuminated output. The sole has two pressure sensitive regions, which vary based on the action i.e. walking or dancing. The input, once crosses the threshold value, leads to change in the display colour. The two areas are the heel and the front part of the foot. This alternate pressure on both these areas during walking or dancing is what creates the interaction. If the person isn’t moving, as in simply standing, the interaction is minimal with no change in colour. The pressole is intended for bold users in a lively setting, such as party hangout areas or even dance studios.

 

Project Context:

During the ideation and concept building phase of this project, I was looking for inspirations from wearables worn by people that have interactive light as an output. The concept of placing a light element on your body that has variable output based on pressure required body parts that exert pressure on a certain surface – foot, elbows, joints. I decided to go with the foot as the pressure exerted by the entire body through the foot on the ground is a decent amount of input with solid values and minimal fluctuations. Before finalizing on this, I did come across this magnificent project where an 8×8 display LED matrix was attached to the hat in order to make a ‘use for all occasions’ sort of hat that can be customized as per need. Link: https://www.hackster.io/hackershack/customizable-led-display-hat-f29bf5

Image: From the project, customizable-light based hat.

 

These fancy light visualizations on the hat are trendy as well as a great way to customize your own look. The visualizations in this project are based on the users need. You can have text, images or visualizations formed by LED combinations. Another project called the ‘Firewalker LED sneakers’ is also a great example of how to customize your looks. These are sneakers with an LED strip that light up as you walk. The LED’s here are in a strip form stuck to the base of the shoe. Link: https://learn.adafruit.com/firewalker-led-sneakers/overview#

Image: Firewalker LED sneakers in action. Source: https://learn.adafruit.com/firewalker-led-sneakers/wear-em 

Both these projects have been great leading points of inspiration that formulated the idea of having pressure as the main key element in order to measure it and creatively depict it in such a manner that it doesn’t seem that technical.

Another great project that had pressure measurement based on the input received from the sole pressure. These soles had pressure measuring sensors stuck onto the base wherein one can step on, and this v=would give a feedback which would then get mapped onto the system. Link: https://www.hackster.io/Juliette/a-diy-smart-insole-to-check-your-pressure-distribution-a5ceae

When I decided to make the pressure sensors from scratch, I also had the idea of creating the shoe as a whole. For this, Troy Nachtigall’s origami shoes came in as a big influence in my project. He has explored with 3D origami shoes (Link: https://troykyo.net/) along with solemaker shoes. These projects broadened my horizon. Another beautiful self-made felt shoe project by a Royal College of Art graduate Gaspard Tiné-Berès has also been influential through my process of ideation.

     

Image Source: https://www.dezeen.com/2012/06/21/lasso-shoes-by-gaspard-tine-beres-at-show-rca-2012/

With multiple inspirations during my ideation, I could clearly see what I wanted to create. With a fixed mind of using pressure sensors, I decided to create them, which were well-documented in the ‘How to get what you want’ website. Link: https://www.kobakant.at/DIY/?p=65

These were made out of neoprene and velostat. The idea was to have these analog pressure sensors to control the LED’s on the CPX based on the threshold value set.

 

Image: Neoprene Pressure Sensor. Source: https://www.kobakant.at/DIY/?p=65

These projects acted as a guiding source for me, in order to take this forward. My idea was something which had a visual feedback every-time the pressure detected was more than the threshold. I was initially planning of having separate R, G and B sections of LEDs that would light up with 4 pressure point areas. But with the availability of materials, I decided to keep it clean with 2 pressure sensors only.

In the final project, the idea is to have a default LED animation with a constant colour. Once there is pressure on the pressure sensors (P1-top and P2-heel), there is a change in the colour of the affected section of the CPX.

     

Here, in the above image as you can see, the pressure on P2 changes the colour of the bottom portion of the CPX. Thus, while walking based on altering pressures on P1 and P2, the visualization has altering colours.

 

The Making – Photos and Images of the process

Step 1: Creating paper cutouts of the construction and stitching. These are the positions of where the P1 and P2 pressure sensors will be getting attached.

      

 

Step 2: Creating a paper flap for proper measurements in order to create a slip on kind of slipper.

 

Step 3: Creating the pressure sensors, using neoprene-conductive sheet – velostat – conductive sheet – neoprene, in that order to create the pressure sensors.

 

Step 4: Stitching the pressure sensors P1 and P2 on the sole.

 

Step 5: Creating the Slip-on attachment for the sole along with a flap for the battery to go in. Then stitching the entire setup onto the base of the rubber sole.

Also, cutting of the base sole of the fabric, in order to cover the path of the circuit that goes underneath.

      

 

Step 6: Stitching the circuit onto the presentable side of the red slip-on cover. The circuit is stitched using conductive wire. The path is taken from the sides of the rubber sole to avoid any contact with the skin.

Close-up shots of the circuit and the resistors attached

 

Parts, Materials, Technical Assets

Parts list & Materials used –

• Velostat
• Neoprene
• Conductive fabric
• Shoe sole
• Fabric
• Stitching thread and needle
• Conductive wire

Technical Assets – 

• Resistors (220 ohms)
• Adafruit circuit playground express
• 8×8 LED Matrix board (for future use) – https://www.creatroninc.com/product/8×8-led-matrix-board/

 

Circuit diagram

Image: Using Fritzing, the diagram of a pressure sensor based input

Here, I made use of velostat pressure sensors in the place of the pressure sensors which were placed in the front and back of the sole. The original idea was to use an 8×8 LED matrix but because of procurement issues, that couldn’t be incorporated. So, instead i have used the inbuilt lights of the CPX which was used here as the main board.

In the diagram below, the top pressure sensor controls the LEDs attached in the top half of the CPX and the heel pressure sensor controls the lower half of the CPX LEDs.

 

Code GitHub 

https://github.com/sanandadutta/Pressole/blob/master/Code

 

Wearability Assessment

The ‘Pressoles’ are made with a mindset of being social wearables. They have input made by a single wearer and the ouput is perceived by both the wearer and others. This falls under the category of expressive wearables but with a single wearer who is the sole input maker.

Source: The Matrix of  who ‘is sensed’ and who ‘senses’ the wearable, from ‘Design Framework for Social Wearables’.

• Placement: Foot
• Form language: Shoe shaped
• Human movement: Walking/Standing/Running
• Sizing: Foot size of the individual
• Sensory Interaction: Pressure due to weight

 

Video of the interaction* (1 minute or less)

 

Challenges & Successes

The creation of this project came at a time when the world was facing a global pandemic. Despite the situation of being confined to the indoors, I took it as a challenge to come up with an output that I originally had in mind, but with the resources I had available with me. I wanted to build the entire setup of the Pressoles with an 8×8 LED matrix, which i did buy. But, as I started creating the setup and planning out the build, I realized, I would need tp solder resistors and use a breadboard along with an Arduino to create the entire setup. Due to lack of availability of soldering tools, I decided to use the Adafruit CPX which had inbuilt microcontrollers and LED’s. This made my setup much more cleaner and easier to incorporate.

Apart from this, I might have chosen a different fabric colour for creating the flaps of the shoe. But, I did have velvet maroon fabric in abundance which proved to be handy in this process.

Overall, I did learn to create out of the resources I had with me. And this was a challenge that I enjoyed overcoming.

 

Next Steps

My current project is made using the CPX at present. But I would definitely love to explore the 8×8 LED matrix and try to create visual animations, similar to one of my inspiration projects. This would make the Pressoles 2.0 with a fancier outlook as an expressive wearable.

 

Bibliography of References