What Problem?

As Americans, we create an enormous amount of trash. The average person produces about 4.4 pounds per day(the global average is 2.6 pounds), and most of it is comprised of recyclable items.

To tackle the trash problem


Using recycled plastic to make new products saves 66% of the energy over using virgin material. Recycling of aluminum cans saves 95% of the energy required to make the same amount of aluminum from its virgin source.

While government and enterprises take initial acts to increase recycling rates, we are seeing this interesting phenomenon: Mixed trashcans always fill faster than recycle bins.

In order to understand what prevents people from correct recycling, two team members did an observation in the Georgia Tech Student Center.

Location: Georgia Tech Student Center, First floor
Time: One hour during lunch peak time

Two recycle bins were in the observation area. Mixed trashcans out-numbered recycle bins and are mostly placed in the open area.


During this one-hour lunch peak, we observed no one putting anything in the recycle bins, but mixed trashcans quickly filled up.

Why did this happen? We had some hypothesis:

  • Location: Mixed trashcans were more accessible -Most of them were in the open area close to where people sit and eat.
  • Ease of use: Most people were in a hurry and didn't even stop when passing by the trash cans. Putting trash in the recycle bins, however, requires extra time reading signs and sorting the trash.

What we learned from our observation

People won't put in extra effort to get rid of their trash -They just go to the closest trashcan and dump the trash without looking.

Mixed trashcans were placed in more accessible locations for a reason: they take less space and improve efficiency in such busy areas. It won't work to replace all of them with recycle bins.


After we figured why mixed trashcans fill faster than recycle bins, the team started brainstorming ideas. We collected more than 20 ideas in 2 brainstorming sessions, and discovered 4 themes.

  • Make recycle bins easier to read and understand
  • Shape trashcans to restrict the objects that go into it
  • Increase motivation to attract people to go extra steps in recycling
  • Educate about trash problem and benifits of recycling

Initial concept

We started to form a concept of interactive recycle bin, which is a combination of several ideas we had.

Validating the concept

In order to better design the experience for a dedicated encironment, we narrowed down our design space to Georgia Tech campus. Because the key to success in our concept is to motivate people by raising a voting contest on trivial arguments, which requires everyone in the neighborhood to have strong ownership of the community. It makes sense to choose a campus environment for it has a strong community nature.

We created the following personas to help us resonate empathy with the users' frustrations, goals, needs, and lifestyles.

We wanted to find out if our users will be truly motivated to vote on trivial topics. So we conducted a validation test to see how much participation can we receive.


Georgia Tech Architecture Building
Georgia Tech Klaus building
Georgia Tech Clough Learning Commons
Over a weekend

In a friday night, we put together 5 sloppy voting boxes and distributed them secretly across the campus.

We retrieved the boxes on Monday morning. To our surprise, we received plenty of notes even there were less people during the weekend.

Prove of concept

The result was absolutely exciting. Not only did we see sticker notes in the boxes, a lot of them were written and commented. It proved that people cared enough that they were willing to spend the time to share their opinions.

At this point, we had solid prove that the core of our idea - "Increase motivation" was working.


Audio Interaction Design

In addition to visual interactions, we designed a series of audio tones for our recycle machine. The audio tones will provide users with prompt feedbacks of valid input, and give hints about whether the recycle was correct or incorrect.

Containers Inserted
Correct or Incorrect?

Sound of containers will immedaiately play once bottles or cans are inserted. Following that, the elevating tone rings if the insert is correct (cans in aluminum, bottles in plastic), and vice versa.

Experience Map

Product Engineering

Now that we have drafted the entire journey, I started designing the physical product.

Next, I built the 3D model on 1:1 scale to get ready for implementation.

System Blueprint

The team spent a lot of time figuring out the technical solutions. I have made this flow chart to explain how our system works.

We Started Building

After several late-night Home Depot runs, our arcade machine started to embody. We built the entire thing with mostly wood boards. The team's favorite part of building was painting the surface and least favorite was sanding it.

Implementing the electronics was painful. We used Arduino to control all the sensors and electronic components. Our processing code runs on a laptop which we hide at the back of the the Kiosk.

The team had fun building it. We took a series of group pictures where we made our faces look like "indifferent, happy, sad" emojis. This joke of "real human-computer interface" inspired the final design of layering acrylic faces on the middle screen and using edge lighting to give feedbacks on correct / incorrect recycling.

Building Complete

After attaching graphics and some final touching, the building was complete. We used fluorescence wire to light the edge in the last minute, it emphasized the arcade feeling and really helped it stand out in the evenings.

Road Tests

We rolled our machine out on the "LaunchPad Demo Day" at Georgia Tech. It attracted a lot of people there to interact with our machine. We put together a clip of that day, and it's just fun to look at.

Video Coming soon.


  • Through this semester long project of interaction design, I learned how to provide intuitive feedbacks for the system to prompt users about further interactions. The audio and visual feedbacks need to be consistent, self-explanitory and occur at the right time. Some usual occasions are recognition, rejection, warning, confirmation.
  • Users may not interact with our product the way we designed to. As occurred in our road tests, people pour water in the recycling machine in order to gain more points for their teams. That ends up wasting water which is the oposite of our purpose (a bug in our code enabled counting multiple points instead of 1 during one liquid flow detection). We should include that thought in the ealier phase and design our system to be more robust.
  • We pivoted a lot in the early ideation phase. The final concept was a result of creative thinking and validated rationale. I experienced very strong epiphany of the power of brainstorming, and hope to bring on more fun ideas in future projects.
  • Good teamwork is more than 1 + 1, it needs to bring together the right skillsets and mindsets.