inflatable Arch

Spatial Design
Interaction Design
Peilin Chen
Inflatable Arch reproduces a prominent icon within Grand Army Plaza at a more intimate scale and invites the public to participate in the augmentation of public space.


The challenge — to create an interactive piece that requires no instructions.

The site — Grand Army Plaza in Brooklyn, a plaza surrounded on all sides by four lanes of roundabout traffic with minimal access points for pedestrians. The plaza serves as a entrance to Prospect Park, and is lined by  various commemorative sculptures, including the Soldiers and Sailers Memorial Arch as well as the Bailey Fountain.

Soldiers & Sailers Memorial Arch and Bailey Fountain.
In our research during a site visit, the strong axiality of the plaza leading to and from the park was evident. Most foot traffic streamed along this axis, with the occasional book reader upon a bench or the sightseer capturing a photo. However, the plaza served primarily as a thoroughfare.

One thing to note is the time of our visit, 2pm on a weekday. We acknowledge the dynamic of the space fluctuates throughout the week, and even the year around seasons.
Behavior mapping of pedestrians on Sept 02, 2023 from 1:15pm to 1:50pm


Despite their size and prominence, the monuments and sculptures of Grand Army Plaza can sometimes become invisible aspects of the landscape to those who frequently traverse the park.

In response, we proposed gathering the monuments in one centralized location so they can be encountered collectively. In their gathered form, they would be scaled down to the height of a person.

Each monument would be an inflatable that takes shape only when a person or a group comes together to inflate it. By design, the inflatable deflates after a short while, coming to life again at the hands of curious passersby seeking to discover its form.
Larger monuments require multiple people working as a team to inflate the form


Inflatable Arch was installed for two hours on September 18th, with help from friends, and enjoyed by passersby.

The pumps were manually plugged in upon interaction with the stepping pads. Each pair of pumps were controlled independently, requiring for a pair of visitors to fully inflate the arch.
Pictured — Arthur Wu, Connor Gravelle, Peilin Chen
Pictured — Molly Chen, Sarah Elstien
Visitors were invited to decorate the arch by adding stickers
Pictured — John Kim


To realize our prototypes, we looked to plastic painter’s tarp as a quick and light material, cut into shapes corresponding to the sides of the form. For seams between panels, we opted for masking tape as it’s easy to use, and allowed for air to escape from the form in a controlled manner.

It was during this time, upon completion of the arch, we realized the time investment, and decided to focus on a single form.
Besides the form, we also considered inflation devices. To maintain someone’s curiosity without losing their attention, or will to continue, we approximated an inflate time of no more 60 to 90 seconds.

This time also depended on the amount of effort required in the inflation — if the method was to pump by hand, attention spans could be extended as the person is physically involved. However, if the method is automatic, the person could lose interest and not gain as much of a satisfaction once the form is fully inflated.

There exists a link between the amount of effort someone puts into an act and the feeling of gratification upon completion. We tested a few of these inflation devices out.
Proposed inflation devices
Inflating manually with a bike pump and inflating mechanically through a hair dryer
Homemade bellow worked well for a a short period of time and was the most promising manually operated inflation device
It was a challenging task to negotiate inflation times versus deflation times. From our testing, the bike pump did not provide enough air flow to sustain the volume. The bellow did, however, but it quickly fell apart due to repeated use. Overall, the hair dryer was the most effective as it was able to deliver a steady stream of air into the form.

In subsequent prototypes, we introduced a funnel shaped valve that increased the air flow based on Bernoulli’s principle. By doing this, we were able to inflate, on average, three times quicker.

At the scale of this prototype, roughly 3ft by 3ft, it took about 10 seconds for the form to deflate. In some tests, we added a valve flap and that time went up considerably, but neither was satisfactory, as we wanted a deflation rate in between the two.
Funnel-like valve that operates off Bernoulli’s principle to increase air flow
Funnel-like valve that operates off Bernoulli’s principle to increase air flow
The initial on-site prototype was set up near the fountain with the intent of determining approachability. The prototype featured an inflated arch with a button of indeterminate purpose, marked with an X.

At the end of the session, we noted minimal interaction, but decided to proceed with a larger version in an effort to attract more people.
The final version of the arch was made using the same materials, with a slightly thicker plastic tarp to protect against tears. Even with the relatively light weight material, we were concerned it would be too heavy to inflate.

In this rendition, the arch would be inflated by four electric pumps, two on each leg of the arch, and activated only when standing upon either pad at the base.
Prepping the material by removing air pockets between two sheets to ensure the most accurate cut
The arched shape was manually measured, drawn, then taped
The arch compacts neatly
Adding the plates that sit atop the plinths. Two holes take in air from the pumps
Everything packaged between the two base plates, along with the stepping pads
Special thanks — Peilin Chen, Karolina Luckiewicz, Arthur Wu, Connor Gravelle, Sarah Elstien