Harrison Lin is the founder of Rhythm, a San Francisco-based company that helps you get healthy light. Rhythm builds hardware that generates the light you need to feel good and software that tracks your light intake throughout the day to build healthy light habits. Their story began during the pandemic with a garage and a light meter. Rhythm’s first product, the Light Machine, is built in-house from CNC-bent sheet metal in a single, warm color temperature.
01 Origin. What problem, frustration, or quiet conviction made your company/product(s) necessary? Take us back to the moment the idea wouldn't leave you alone.
I started prototyping light machines during the pandemic, when we were all stuck inside on Zoom calls. I was feeling exhausted during the day and struggled to fall asleep at night. I knew something was off. It turns out that I was seasonally depressed. I’m typically a really energetic and optimistic person, but in that period of my life, I felt tired, sluggish, and uninspired simply because I wasn’t getting enough light.
I bought a light meter and learned that I was getting 1000x less light indoors than outdoors. That’s when I realized how much light affected my mood, health, and wellbeing. I wanted to get outside, but the reality was that I was glued to my computer ten hours a day. I’m a mechanical engineer, so I started tinkering in my garage, trying to develop a solution that could benefit anyone, anywhere. This tinkering turned into Rhythm.
Rhythm builds hardware that generates the light you need to feel good and software that tracks your light intake throughout the day. We serve the hundreds of millions of people who suffer from seasonal affective disorder worldwide, as well as anyone who just wants to feel better during the day. I tell people that I’d love for everyone to spend more time outside and get light naturally. But if you’re unable to get outside due to your job; due to it being too cold or rainy; or due to just being down and depressed, Rhythm is here for you.
There’s a lot of suffering in the world that we can help alleviate. I envision Rhythm in every home, office, classroom, and hospital—anywhere people are obligated to spend lots of time indoors. There’s a future where everyone gets the light they need to feel happy, healthy, and well.
02 What you were doing before. What were you doing before this, and how did it prepare you, or fail to prepare you, for what you're building now?
I had a career as a mechanical design engineer at startups like Carbon 3D. While there, I learned how to design parts from sheet metal, machine, and print. All of these experiences influence how Rhythm machines are designed and constructed today. Moreover, I wanted to further understand how to design my own products, so I attended Stanford’s design school. Both my love for mechanical engineering and product design prepared the foundation for me to build the best possible product at Rhythm.
03 The constraint that shaped it. Every well-made object is defined as much by what it isn't as what it is. What was the hardest constraint you worked within, and how did it sharpen the final product?
The biggest constraint for the Light Machine was the fact that we wanted to build a high-quality product with zero fixed tooling. We were able to accomplish this by making everything out of aircraft-grade, CNC-bent sheet metal. This way, we could keep the design iteration costs low while making the most beautiful version of the product possible. Currently, we build everything in-house in our workshop in San Francisco; this helps keep quality standards high. Because our team has full design and manufacturing control, we can move quickly and ship the best possible version of the product.
04 A design decision you defended. Walk us through one choice that was questioned, debated, or pushed back on, and why you held the line.
The Light Machine has a single, warm color temperature. It’s about the same vibe as golden hour sunrise and sunset. Many people have asked why we don’t have adjustable color temperatures like other lights. The reason is that we’re able to fit the highest light density and lighting efficiency by keeping one color temperature. By introducing more color temperatures, we’d either need to double the size of our product or half the intensity; both are unacceptable tradeoffs. I think our design decision keeps the user experience as straightforward as possible while comfortably delivering on the promise of high amounts of light density. It’s just a better user experience.
05 What you removed. Form and Function lives in what's left after the cuts. What did you take out, leave on the cutting room floor, or refuse to add?
One big discussion we had as a team was the CMF of our touchpoints, specifically the dial cover and the grip that we put on handles. In earlier prototypes, we used 3D printed matte filament for these parts, which looked decent but felt fairly crummy compared to the powder coated sheet metal surrounding it. So, we opted to remove the printed handles in favor of the bare sheet metal; and we’re currently moving towards a metal CNC-machined dial cover to improve the texture and feel of that touchpoint. It costs us more to make, but it’s completely worth the extra effort for the best possible experience.
06 A make-or-break moment. Walk us through a moment you weren't sure you'd make it through. What got you to the other side?
We really panicked a bit while getting our product FCC certified. We initially thought we’d immediately pass with flying colors, but it turns out that some of the components we were using had claimed to pass FCC testing but actually fell quite short. This caused our product to fail. So, we had to scramble to come up with replacement parts and design changes. It took us weeks of troubleshooting and hours and hours wasted in the testing lab (which cost us a small fortune) before we fixed the root cause. What got us to the other side was asking some of our electrical engineering friends to brainstorm potential paths. Thankfully, we found a solution and passed easily with those fixes.
07 Who you look at. Whose work do you look at when you need to remember why you started? What brands, designers, or thinkers shape how you see things?
I quite admire companies and brands that think deeply about solving essential problems and solve them to the maximum extent possible. For example, anyone can make a vacuum, but Dyson makes an incredible vacuum that completely and thoroughly solves the issue of cleaning your home. Rhythm wants to be the company that builds incredible light machines, developed out of an obsession over helping people get healthy light.
Teenage Engineering, Dyson, Eight Sleep, CW&T, and (of course) Apple are all inspirations for what we do at Rhythm. I admire artists like Isamu Noguchi, Larry Bell, Dan Flavin, and James Turrell, who are all artists that have developed a relationship with light in their work.
Lastly, health influencers like Bryan Johnson and Andrew Huberman have shaped my relationship with light health. Their findings have helped influence what type of product I like to build and elaborated on why light is an important factor in people’s everyday lives.
08 What's next, and what stays the same? Where is the brand going from here, and what will never change about how you make things?
I’m very excited about our Daylight Savings product launch this year. By the time you read this, our product will have launched on Bryan Johnson’s Protocol Marketplace. I’m so excited for the world to experience our product. We’re a small team trying our best to deliver an amazing experience to our first customers.
The next versions of our products will be designed for tooling to meet volume and cost targets to make the product more accessible. So, future versions of the light machine will hopefully be smaller, more efficient, and more affordable. However, what will never change is our commitment to performance, build quality, and a delightful user experience.
09 Who's next? Name one or two founders, makers, or studios you think is making products that beautifully marry form and function right now. Someone we should be paying attention to, and why.
One of the team members at Rhythm recently introduced me to Daisy Audio. They sell noise-cancelling headphones that have an insanely beautiful build quality and integrated user experience. I think they’ve done an amazing job with the polish of their first launch (at a price point that nobody can complain about).
I’m also excited about Stream Ring by Sandbar. I personally know Mina and think that they’re doing an amazing job elevating what consumer hardware looks and feels like.
Lightning Round
An object you'd never replace
My Noguchi lamps.
A book, film, or album that shaped how you think about design
The film Perfect Days helped me understand that design should be the pursuit of “simple done well.”
A daily ritual
Waking up to sunrise on my Rhythm Light Machine. No alarm!
The last thing you bought that surprised you
I bought these handblown glass oil lamps from Wolfard Glassblowing Co. that emit a beautiful glow in the evenings (when I especially want to keep my light intake low). The design is mesmerizingly simple and beautiful.
A piece of advice you'd give to someone making their first product
Do whatever you need to get the idea out of your head and into reality. You’ll learn so much more by making five terrible physical versions than going through thirty digital iterations.
Coffee order
One & one (split shot macchiato) with sparkling water on the side.
About FORM & FUNCTION
Form & Function is a print magazine about the objects worth keeping. We write about the tools, gear, and everyday things that earn their place through good design and honest craft — the stuff that works as well as it looks. Each issue is made slowly and on purpose: matte pages, considered writing, no filler. This newsletter is where that same thinking shows up between issues — founder interviews, early looks, and the occasional thing we can't stop thinking about.
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FORM & FUNCTION — Issue 001.
The quarterly print magazine about things worth keeping. Matte, printed, made to be held. Ships August ‘26.