Asseyez is a stool that remembers being sat upon using a mechanical counter. The cushion's thermochromic leather changes color based on body heat.

Designed and manufactured in the Product Realization Lab at Stanford.


Steel, maple, plastic, thermochromic leather


Welding, turning, milling, sewing

Before someone sits down, the seat is a consistent orange:

When someone has recently sat on Asseyez, their heat pattern is momentarily visible on the cushion and the counter is incremented:

Design Process


I decided to build a stool that could answer two questions. “How many people have ever sat on this chair?” and “When was the last time someone sat on this chair?”

Initial designs varied between 3 and 4 leg designs with the spring and counter sandwiched in various ways. The design evolved to a single tube with a spring at the base which would be compressed by a smaller telescoping tube.

The use of a mechanical counter was important to me as I wanted the counting interaction be entirely analog.


Early wood prototype:

Testing the thermochromic properties of the seat with the warmth of my face:


Welding the metal pipe to sheet metal:

Using a router on the maple seats:


Going through the entire product realization process from an idea to a real physical stool has been immensely rewarding. It's empowering to know that I bring my ideas to reality.