Prototyping Challenges In Engineering Projects

Flexible pressure sensors are everywhere in prototypes. But scaling them to real-world production? That’s where most projects fail. In our work designing pressure mapping systems for robotic end effectors, we faced two challenges at once: → Build a high-fidelity, flexible sensor array. → Make it manufacturable beyond the lab bench. Here’s what it took: → Material System Selection. Why? We couldn’t just pick the softest or thinnest FSR materials. We needed materials that could survive lamination, mechanical cycling, and environmental stress without losing responsiveness. → Matrixing Without Crosstalk. Why? In a grid of distributed sensors, each node needs to be individually addressable without electrical interference bleeding across rows and columns. We engineered trace geometries and insulative layers to keep signals clean — even under flex and inflation. → Layered Durability. Why? Flexibility often sacrifices lifespan. We designed stackups that maintained elasticity while protecting conductive layers from mechanical fatigue and delamination. → Manufacturing Alignment: Why? Prototyping with hand-aligned layers is easy. Scaling requires layers to be aligned mechanically or laser-cut to tight tolerances, without introducing shifts that ruin sensor performance. It’s not enough to build a working prototype anymore. If you want to move from a concept to something scalable, you have to engineer for: → Mechanical reliability → Electrical integrity → Production repeatability

A $12 prototype can make $50,000 of engineering analysis look ridiculous A team of engineers was stuck on a bearing failure analysis for six weeks. Vibration data, FFT analysis, metallurgy reports - they had everything except answers. The client kept asking for root cause and the engineers kept finding more variables to analyze. Temperature gradients, load distributions, contamination levels, manufacturing tolerances. Each analysis created more questions. Then the intern did something that made the engineers feel stupid. She 3D printed a transparent housing and filled it with clear oil so the engineers could actually see what was happening inside the bearing assembly. Took her four hours and $12 in materials. They watched the oil flow patterns and immediately saw the lubrication wasn't reaching the critical contact points. All their sophisticated analysis was based on assuming proper lubrication distribution. Wrong assumption. Six weeks of wasted effort. The visual prototype didn't just solve the problem - it changed how the engineers approach these types of investigations. Now they build crude mockups before diving into analysis rabbit holes. Cardboard, tape, clear plastic, whatever works. Physical models force you to confront your assumptions before you spend weeks analyzing the wrong thing. Sometimes the cheapest prototype teaches you more than the most expensive simulation. #engineering #prototyping #problemsolving

Designing hardware products. The idea that you can simply create 1 or 2 prototypes and then just jump into full production is a big myth. The reality is very different, Using arduino/raspberry pi/STM32 and having something to show is just the beginning of the long journey in designing hardware products. What you have at this stage is usually more or less a proof of concept(POC). More often than not, you cannot ship a product to consumers with this design . A POC prototype cannot simply be bought and be brought to market. This often also most likely goes for many 3D printed designed projects. They are useful for helping to quickly build something and seeing if the idea makes sense at first. The next stage will involve designing a preliminary production design. You will need to come up with a system level block diagram and design your circuit diagram and come up with your PCB design. You order your PCB prototypes, 3D print the mechanical parts and buy other electro-mechanical components. Remember at this stage, you have not mass-produced anything. The PCB prototype and mechanical design fabricated would most likely not work as expected in the first try here. You will go through several iterations, fix bugs and run to other issues you least anticipate. Once you pass this stage, you can design your 3d Model custom enclosure which you may 3D print or use CNC machining as a prototype. Some people call it a Works-Like Prototype or you can call it a pre-production prototype. It is usually a little close to the final product your customers will see. The next stage is now testing and validation. At this stage, you will need to produce more units, about 10-50 units of your product. You may have to start working with your manufacturer and industrial designer at this stage. The goal of this stage is to validate that the working-prototype meets the functional, performance, and reliability specification. It is called Engineering Validation Testing (EVT). The next stage is design validation. You need more units here (usually more than 100 units).You obtain electrical certifications and necessary safety certifications. Depending on the country you want to sell, the certification differs and you need to obtain all this.  You validate it meets necessary design and environmental specifications. An issue or problem observed at this stage can take you to the beginning of the process again to correct your electrical or mechanical designs. Once you are done with these 2 stages, you can proceed with mass-production through manufacturing to create the final product. This is a simplified process for any consumer hardware product you may see. It holds true for robotic systems and products too. That is why you should validate and can even pre-sell with your potential customer first before any prototype. Don't start finding customers after you have a production-ready product. You are more likely to fail by doing this.