Friday night was our first major exhibition and I would say it was quite a success. We opened our studio to the public and exhibited all 9 projects from our month long TUI course.
Keep reading to see photos of a few of the project…
What is it?
Our project is a scale that measures a food product’s environmental impact. It looks at the carbon emitted as a result of transporting the food and measures this in terms of how many trees would be required to offset that carbon over one year.
Who is it for?
The scale is an exhibition piece intended to make the general public think about the environmental implications of the food they purchase.
Why is it valuable?
This scale is an exploration in how tangible interfaces can be used to interact with data on the web. With the increase in usage of RFID technology and as “everday” objects become networked, we anticipate access to untold amounts of information for things as simple as an apple. With appropriate ways to interact with this data, we hope people will be able to make more informed decisions that will help build a sustainable world.
As an exhibition piece, this scale will raise questions about the food you buy, where it comes from and how it is transported. With a subject as complex as carbon emissions and the global food economy, our scale is only an entry point and is intended to raise more questions than it will answer.
This scale can also be viewed as a hypothetical kitchen appliance or point to a future grocery store service. The data it uses is important but remains hidden to most people, and we hope this will not be the case for much longer.
How does it work?
The scale works by looking at the carbon emitted by transporting a particular product from it’s country of origin to Denmark. Place an RFID tagged product on the appropriate arm and try to balance the scale with the tree shaped weights. The amount of trees used to balance the scale represents the number of actual trees it would take to offset that product’s carbon emissions over one year. Swap items on the scale and compare different items from a particular country or similar items from different countries.
What were your key learnings?
Our team experienced many challenges in assembling the scale and in gathering the data behind the products, but most of our key learnings came in the beginning of the project. Rapid prototyping and user testing were essential for our team. We learned that building rudimentary models is the best way to test rudimentary ideas. Some models told us when an idea was going in the wrong direction while other models told us this only when in the hands of people outside our team. From the beginning, our project was heavy with metaphors - a scale and weights to measure data, and trees to represent this data. User testing was the only way to know if these metaphors were the right choice.
Many thanks to Vinay Venkatraman for working with us on weekends and evenings.
For more information about this project and course, please see my blog archive for TUI
The big task of last week was moving from the foam-core prototype to one made out of acrylic so that we can begin attaching the motor and other electronics. The version pictured above was drafted with AutoCAD and cut on the laser printer. It contains no gears but demonstrates how all the joints will work.
As someone whose background is in digital media, it has been a lot of fun watching Sid and Eilidh (both product designers) build stuff with their hands (and the laser cutter). This is a process I will be careful to never underestimate in any future projects.
Once we were happy with the way the scale moved, we had to begin thinking about how to attach the motor. We considered using a belt system, but once we discovered a discarded printer in the school’s dumpster, we began experimenting with the gears inside that. In the end we decided to attach a gear taken from the printer to the scale and laser cut a smaller gear that would attach directly to our motor.
At this point, Sid has found a new best friend in the laser printer. We are using this tool to do everything from etching text to cutting highly customized gears. But besides using the laser printer, we have been in the electronics labs soldering wires, the wood shop seeking advice on materials, the metal workshop cutting screws, the glass studio sand blasting acrylic and in the IT office seeking discarded printers to hack.
The problem we are currently facing is power. Once the motor was fixed to the scale and connected to our Arduino board, we were very relieved to see that it was actually working. The gears fit and the motor moved the arms quite smoothly. But the problem was it could hardly lift a plastic dish, let alone anything that would be placed in that dish. We experimented with stronger power supplies but in the end the problem appeared to be with our motor’s driver board. We are presently working with Vinay to assemble a driver board capable of handling more power. Hopefully then the scale will actually be able to move with things placed on top of it.
Besides the motor, we also connected two limit switches. They are placed below the gears and act as a safety mechanism. Once the arm goes too far to either side, it will hit the switch and turn the motor off. They will also be necessary for measuring the amount of steps the motor will take to move the scale from one side to the other. With this measurement, we can begin thinking about how to calculate the movements that will take place when different food items and weights are placed on the scale.
We have made some good progress during the past week but our to-do-list is still frightengly long (and getting longer). Once the motor is working properly, we will need to attach an RFID reader to one arm and a load cell (weight sensor) to the other. And then we have to program everything. It also might be good if the object looks nice, as opposed to clear acrylic with wires everywhere. And then we have to put together a presentation.
On Friday each group presented their concepts and current prototypes to the class. We discussed the evolution of our scale and demonstrated the current prototype. The initial reaction was a lot of confusion. People saw our object as a balance for comparing two objects and not a scale used for measuring. People were also confused by the metaphor of weight and how this can be used to measure a product’s environmental impact. How can we clarify the metaphor of a scale? How can we better present the “weight” of a product in terms of environmental impact?
After the last group presented, we quickly got on with our Friday night.
Eilidh, Sid and I got together over the weekend to discuss the feedback from our presentation. We brainstormed ways we could move away from the scale metaphor, but with the course half way over, we decided it would be best to carry on.
On Monday we moved away from the traditional balance and decided to use the form of a mechanical scale. Sid created this 2D prototype out of foam-core to demonstrate the mechanics of the arm.
With two weeks left, it is time to begin the electronics. It is often cheaper to buy a consumer product and take it apart than it is buying a single component from an electronics distributor. In this case be bought a digital scale from Ikea so that we could use the load cell sensor.
Finally we made a 3D model of the scale to better understand the mechanics, size, where to hide the electronics, motor, etc…