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01 / 08

Venture · 2024 to now

Opensip

A reusable straw you can actually clean

Opensip splits open along a magnetic seam, so you can wash the inside like a dish. A friend and I started it in 2024, and it’s now being tested in cafés near my school in Jeju.

10cafés testing
10friends testing
2pricing models
02 / 08

Where it started

My own contradiction

I’d carry a tumbler to the café for the planet, then grab a plastic straw anyway.

I had a reusable straw. I just didn’t want to use it, because it never felt clean. When I looked around, my friends were doing the same thing. The problem wasn’t that people didn’t care. The straws were annoying to wash.

03 / 08

The problem

You can’t scrub a tube

After a smoothie or a sugary drink, the thin brush that comes with most reusable straws still left spots I could see. Dirt comes off when something physically touches it. Water and soap alone don’t get there.

A typical reusable straw

  • A thin brush pushed through a closed tube
  • You can’t see whether the inside is clean
  • So people give up and take a plastic one

Opensip

  • Opens fully along its length
  • You wash both halves like a dish, with a sponge
  • Magnets snap it shut so drinks don’t leak
04 / 08

How we made it

Paper to plastic

  1. Sketch by hand

    My friend and I drew the first design on paper. The 3D Art class I took in ninth grade helped here.

  2. Turn it into a file

    The teacher who runs our school’s 3D printer showed us how to convert a hand drawing into a 3D model.

  3. Find the magnets

    That same teacher helped us figure out where the magnets should sit. Then we found a supplier for tiny, strong neodymium magnets.

  4. Print and try

    We printed prototypes at school and started using them ourselves.

Early concept sketch of the two straw halves
An early concept sketch of the two halves
05 / 08

First version

Too thick?

The first 3D-printed prototype came out thicker than a normal straw, and it felt strange in my mouth.

Then I kept using it, and I got used to it quickly. So we kept the shape as it was.

Opensip prototype
06 / 08

Field test, in progress

Real cafés, real cups

10cafés near my school in Jeju
10friends trying it out

Deposit and return

Customers pay a deposit, use the straw, and bring it back. Owners told us this adds too much work behind the counter.

CAFÉS PREFER

Branded merch

The café sells Opensip with its own logo printed on it. Owners said they’d pay extra for the logo, since customers care more about the environment now.

07 / 08

What I still need to learn

Making it cheaper

  • Production

    How to move from a school 3D printer to real manufacturing, so each straw costs less to make.

  • Pricing

    What a café will charge, what a customer will pay, and whether the logo really covers the gap.

  • Getting the word out

    How to get Opensip in front of people beyond the cafés I can walk to.

08 / 08

The picture in my head

Next to the register

A jar of Opensip straws by the register, and every so often, a stranger in my neighborhood using one.

Run a café and want to try it? Email me: syan27@kis.ac

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