Module 2 Activity Research

Weekly Activity Template

Olivia Weiss

Project 2

Module 2

In Project 2, we are expanding on our initial exploration from Project 1 by continuing to develop our concept and research through physical computing. Building on our previous idea of an exercise band that adjusts air pressure to create varying resistance levels, our focus is on using external sensors to prototype interactive experiences that support physiotherapy recovery. We are currently exploring how to connect an Arduino with an air pressure sensor and link this data to a ProtoPie app that visualizes and tracks pressure levels. This stage of development shows experimentation with sensors, data, and interface feedback. Although we have not yet finalized all findings, our goal is to create a system that connects physical input and digital tracking, enhancing user engagement and recovery monitoring.

Workshop 1 Geurilla Prototyping I

The workshop began with an introduction to guerrilla prototyping, emphasizing quick, low-fidelity methods to test ideas rapidly. We watched a video that showed us how to make a phone stand using simple materials like cardboard. We followed along, cutting and assembling our own stands while learning the importance of speed and simplicity in prototyping.

This is the view of a phone stand created from a different video tutorial. It highlights the variety of designs that can be achieved using guerrilla prototyping techniques. The focus is on functionality and ease of assembly rather than aesthetics, allowing for quick iterations and testing of concepts.

This is the finished design of the second phone stand tutorial. It showcases the final product after following the step-by-step instructions from the video. The design is simple yet effective, demonstrating how guerrilla prototyping can lead to practical solutions with minimal resources and time investment.

This design is a varitation of both the first and the second phone stand tutorials. The aesthic is similar to the first tutorial. We added a phone charger hole to the design to enhance its functionality. This modification shows how guerrilla prototyping allows for easy customization and adaptation of existing designs to better meet user needs. We then added a second side to it to make it so two phones could be propped up at once, this was taken from the second tutorial.

This is the final design of the phone stand that combines elements from both tutorials. It features a sturdy structure with a built-in phone charger hole, allowing users to charge their devices while using the stand. The dual-sided design accommodates two phones simultaneously, making it versatile for various use cases. This prototype exemplifies the principles of guerrilla prototyping by being quick to assemble, functional, and easily modifiable.

Workshop 2 Geurilla Prototyping II

This was the starting point for our first attempt at prototyping our exercise band concept. We got cardboard and cut out circles to see if we could actually create the gears out of cardboard. This helped us understand the dimensions and mechanics of the gears we wanted to create.

This image shows the holder where the gears would be placed. We created this piece to see how the gears would fit together and to test the overall structure of our prototype. It was important to ensure that the gears could rotate smoothly within the holder.

This image shows that we need to have something inbetween the gears to keep them from falling through the holder. We decided to add a piece of cardboard in between each gear to provide stability and ensure they stayed in place while rotating.

This is what the gears looked like after we cut them out of cardboard. We made sure to create teeth on the gears so they could interlock and rotate together. This step was crucial for testing the functionality of our gear system.

This is showing how the gears would look when placed in the holder. We tested the rotation of the gears to see if they meshed well and could turn smoothly without any obstructions.

Activity 1: My Research

Julie and I used the tutorial, 'How To Upload and Run Code on an Arduino - Getting Started with Arduino' to help us easily set up the Arduino interface.

After successfully connecting the Arduino, we found a tutorial that showed how to connect the same air pressure sensor we had. We were able to follow the tutorial, but we also had to go to external sources to find the right code for what we wanted to achieve.

To get the Arduino and air pressure sensor working, we searched for additional wiring diagrams and code examples that fit our needs. We ended up connecting VCC to 3.3V instead of 5V because the Arduino would turn off when using 5V. After researching, we learned this usually means the sensor is drawing too much current or there’s a short circuit.

After further research, we were able to get the serial monitor to display dynamic pressure data that changed according to the timing intervals set in the code. When we blew into the sensor, the pressure readings increased accordingly.

Julie and I wanted to explore the Arduino and pressure sensor further. We brainstormed ways to visually indicate different air pressure levels and decided to use LED lights. This setup provides real-time feedback, with each LED lighting up according to the pressure detected by the sensor.

We found a tutorial that used a different sensor but also displayed data with LED lights, which aligned with our goal for this activity. It helped us set up the Arduino with both the LED lights and our sensor.

We wanted to clarify a few things about the breadboard, so we revisited our Project 1 documentation from the in-class activity. This helped us recall the positive and negative sides of the LED lights and what needs to be connected to the ground. It also refreshed our understanding of resistors.

Our first attempt was unsuccessful. We connected the sensor to the Arduino as we had in the previous activity and followed the video to connect the LED lights and assign pin numbers. However, the Arduino setup in the video wasn’t fully shown, so we had trouble figuring out how the grounds were connected. Connecting the negative sides of all three LEDs to a single ground pin was incorrect and caused only one LED to light up.

We revisited photos from an in-class activity with Steve, which cleared up our misunderstanding and allowed us to correctly connect all the grounds.

After fixing the wiring, our setup was successful. The left LED represented low pressure, the middle LED medium pressure, and the right LED high pressure. When I blew on the sensor, the middle LED lit up.

Activity 2: My Research

For this activity, Julie and I aimed to build a simple version of our final prototype to mimic our smart resistance band concept. Our goal was to test whether the sensor could continuously track air pressure and detect changes when the airbag was squeezed.

We blew air into a plastic bag to simulate an air pump. We cut a small hole in the corner of the bag, inserted the tube, and sealed the bag to prevent air from escaping. Although this method worked in our first activity, the sensor did not provide accurate pressure readings this time.

Since our setup had worked earlier but failed this time, we suspected we might have accidentally changed something in the code. We used ChatGPT to help troubleshoot the code and identify the issue.

We followed the tutorial steps as closely as possible, but while reviewing it, we noticed that the presenter also had issues with her sensor. She suggested the sensor might be picking up noise from touching the walls of the bag. Since we used a tube and did not submerge the differential pressure sensor, this did not apply to our setup. We concluded that the issue was likely because our pressure sensor was not capable of measuring the higher pressure.

After concluding that our sensor was the issue, Julie and I researched alternative sensors. The MPX5010 seemed the most reliable, but it would not arrive in time for us to test and integrate it into our final prototype. We also checked with several stores but had no luck finding it or a similar sensor. After further research, we found the MPXV7002 sensor. We reviewed tutorials and articles on how it works and how to set it up, and have ordered it. We are now waiting for it to arrive so we can test it.

Additional Research or Workshops

Pneumatic artificial muscles work like real muscles — when air pressure increases, they contract and get stiffer, creating more force. They’re soft, flexible, and safe to use, which makes them perfect for something wearable. For the band, this same idea could let you adjust how tight or resistant it feels just by inflating or deflating the air chambers. Instead of relying on elastic tension, it uses air pressure to create a controllable, natural resistance that won’t cause strain or sudden tension.

The McKibben muscle model uses a rubber inner bladder wrapped in a braided mesh. When air is pumped in, the bladder wants to expand outward, but the braid stops it from doing that. Instead, the whole thing shortens, creating tension — kind of like stretching an elastic band, except the force comes from air pressure instead of rubber.

The soft silicone actuator is a modern, wearable version of a PAM — it still uses air compression to generate tension, but it replaces the braided mesh with layered silicone and built-in friction systems to better control stiffness and movement.

The actuator brings three systems together to make it work like a smart muscle:
Actuation: the air chambers expand and contract to create movement, just like a muscle.
Resistance: friction between the soft layers increases with air pressure, controlling how hard the band is to stretch.
Sensing: built-in sensors track stretch, stiffness, and effort to give real-time feedback and adjust resistance automatically.

When air is pumped into soft silicone actuators, they can sometimes “balloon” or bulge instead of bending smoothly, which wastes energy and can cause damage. To fix this, different materials were tested: thicker walls and stiffer silicone helped but created new issues. The best solution was adding a thin PVC reinforcement layer, which completely stopped ballooning and kept the motion smooth. Overall, this simple reinforcement makes soft pneumatic actuators stronger, safer, and more reliable for wearables and other applications.

Project 2

Project 2 Prototype

Throughout this project, we expanded on our original idea of an adjustable resistance band by exploring how physical computing could bring it to life. The workshops helped us build our cardboard prototype through geurrilla prototyping, which let us quickly test form and function. The activities focused on the technical side, helping us understand how to use the air pressure sensor and the Arduino to collect data. We ran into some issues with the pressure sensor and spent time troubleshooting, and we’re now waiting for a new one to see if it works better. Overall, this project taught us a lot about connecting physical components with digital feedback and how technology can support interactive recovery experiences.

Once we finished all of our activities and research, we met as a group to create our final prototype. We enhanced the prototype Brianna made in her Activity 1. Brianna made a list of changes that should be made to it, I drew a diagram of what the prototype should look like and Julie created the prototype.