This week, I focused on finalizing our design slides and collaborated with Jess and Sarah to thoroughly review our hardware components for the presentation. We ensured that all elements were clearly documented and that our explanations were concise and well-supported. Additionally, after internal discussions and consulting with a Master’s-level Mechanical Engineer experienced in working with pressure and weight sensors in various projects, we decided to transition from force-sensitive resistors (FSRs) to weight sensors for greater accuracy and reliability. To support this shift, I began exploring different weight sensor options that align with our design needs. However, we are concurrently testing pressure sensors to validate our decision, as we have acquired square and small circle pressure sensors from the Ideate lab for evaluation.
Our decision to move away from pressure sensors stems from their inherent limitations in detecting stacked items. Pressure sensors measure force per unit area, meaning that if the added item distributes its weight over a large surface, the overall pressure change might be too minimal to register accurately. This could lead to unreliable or inconsistent readings. In contrast, a load cell strain gauge directly measures total force applied, making it far more effective at detecting subtle weight changes due to stacking. By using a load cell, we can ensure a much more precise and responsive detection system, which is crucial for our application.
In addition to refining our sensor choices, I addressed concerns regarding the fabrication of our electronics with FDA-safe silicone. On Thursday, I met with Cody from Ideate to discuss the scope of our project, our progress so far, and the feasibility of using food-safe silicone for the final product. We received great news—facilities are available to help us create silicone molds using FDA-compliant materials, as the Creative Soft Robotics class is currently working on similar projects involving silicone mold printing. Cody demonstrated how straightforward the process would be, as long as we finalize the sensor layout.
The decision to use a weight sensor aligns well with this fabrication plan, as we can calibrate it precisely to account for any pressure applied by the silicone casing. Additionally, Cody helped us select free acrylic sheets that I can laser cut (since I already have clearance for laser cutting) to create plates for sandwiching the strain gauge weight sensor. This setup will provide a stable and effective means of integrating the sensor into our final design.
Looking ahead, I plan to begin drafting the design report since the deadline is quickly approaching. Simultaneously, I will start assembling the prototype with the team to ensure we have a functional version before spring break. Having a physical build will give us a much clearer understanding of any potential integration challenges, allowing us to refine our design early in the process. We’re making steady progress, but accelerating our pace now will help us stay ahead of upcoming deadlines.