How a Smart Mug Uses Heat to Display Your Photos

If you’ve ever wanted your morning coffee to do more than just wake you up—like displaying a favorite photo or motivational quote—the MUKI smart mug might be for you. But rather than relying on batteries or screens that drain power, this cup uses a clever mix of old-school thermodynamics and new tech to bring your images to life, only when it’s hot.

The MUKI mug displays images only when filled with hot coffee, thanks to a thermoelectric generator (TEG) that converts heat into electricity to power its E Ink screen. No power source is needed beyond the heat of your beverage.

What Is the MUKI Smart Mug?

The MUKI mug is a collaboration between a Finnish coffee roaster and an advertising agency. Its standout feature is an E Ink display screen embedded in the ceramic surface. Unlike conventional screens, E Ink doesn’t use much power and only updates when needed. The twist? The image on the mug only becomes visible once you pour in hot coffee.

How Does the MUKI Mug Work?

At the base of the MUKI mug sits a TEG (thermoelectric generator). When you pour hot coffee into the mug, the rising temperature is transferred to the TEG, which converts the heat into small amounts of electricity. This energy activates the E Ink screen. A built-in temperature sensor detects the heat and triggers the display to show a preloaded image. Each time you refill the mug with hot coffee, a different image can appear—ideal for rotating through photos, quotes, or artwork.

The mug also includes a low-energy Bluetooth module. Through a companion smartphone app, users can upload new images, swap out displayed pictures, and even share their mug’s display on social media. All settings, including image selection and display preferences, are managed via the app.

What Can You See on the MUKI Mug?

Users can customize the mug’s display with any image or text they choose—whether it’s a cherished personal photo, a motivational message, or seasonal artwork. The E Ink technology ensures the images are visible but not high-definition or in color. That means no vibrant photos, but also very little battery drain or screen burnout.

In addition to showing images, the mug’s built-in temperature sensor informs you how hot your coffee is by displaying the current temperature right on the cup’s surface. This helps avoid burnt tongues while adding a functional layer to the experience.

Availability and Testing

As of the original report, the MUKI mug had not yet entered full commercial production. The creators were running a testing phase, seeking 2,500 testers for a beta program. Assuming the hardware performed well during trials, the goal was to release the mug in the Finnish market by 2015.

Frequently Asked Questions

How does the MUKI mug display images?

The MUKI mug uses a thermoelectric generator (TEG) at its base to convert heat from hot coffee into electricity. This power activates an E Ink screen embedded in the mug, which then displays images uploaded via a smartphone app. The images only appear when the mug is filled with hot liquid.

Do I need to charge the MUKI mug?

No, the MUKI mug does not require charging. It is powered entirely by the heat of the coffee you pour into it. The TEG converts that heat into enough electricity to temporarily run the E Ink screen.

Can I use any photo on the MUKI mug?

Yes, users can select and upload any image or text through the companion app. These images are then stored and displayed on the mug’s E Ink screen whenever it is filled with hot coffee. The display supports standard-resolution images, not high-definition or color ones.

Is the MUKI mug available to buy now?

As of the report, the MUKI mug was still in the testing phase and had not been released commercially. The creators were looking for 2,500 beta testers, with plans for a possible 2015 launch in Finland if testing was successful.

Does the MUKI mug show the coffee temperature?

Yes, the mug has a built-in temperature sensor that detects how hot the coffee is and can display the current temperature on the E Ink screen, helping you avoid drinking coffee that’s too hot.

Recommended FrontStreet Beans for MUG Enthusiasts

If you’re sipping from a smart mug like the MUKI, match it with FrontStreet Coffee’s Ethiopia Humbera for bright citrus and floral tones, or Yirgacheffe for juicy berry and stone fruit layers. Both single origins shine in pour-over or filter brews and complement the tech-meets-tradition vibe. For something richer, try the PWN Golden Mandheling with its deep chocolate and caramel backbone. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.