Lego Sherlock Holmes figure focuses a light beam on a Lego criminal with a small magnifying glass.

LEGO Aromatherapy

The LEGO Aromatherapy machine.

Our staff here at works tirelessly to develop new LEGO-based technology for defense and security applications. But sometimes we take time out to enjoy the finer things in life. So here is a LEGO scent diffuser for aromatherapy. This device is based on two components: a fan and a water atomizer, both under EV3 control. The water atomizer is shown in action in the video below. This is based on the Grove Water Atomizer that vaporizes liquid with ultrasound. The water atomized in this case has a few drops of essential oil (I like lavender) added to scent the air. Liquid is fed to the atomizer by placing the ultrasound transducer on top of a cotton swab saturated with the water/oil mixture—the transducer shouldn’t be submerged or floated on liquid. I accidentally destroyed a transducer by letting it get dunked in water. The water atomizer is interfaced with the EV3 Intelligent Brick by a Grove Sensor Adapter ( This Grove Sensor Adapter described in detail in a couple projects in “High-Tech LEGO.” Also used from Grove is the Grove Wrapper, as in my blog post on “Grove LEGO Adapters.”

The 2nd component is a fan to spread the atomized water/oil vapor. I used a design for the fan from Yoshihito Isogawa’s book “The LEGO Mindstorms EV3 Idea Book.” As in the video below, once the atomizer has a few seconds to produce a steady mist, the fan is activated to spread the aromatherapy.