When desiccation device needed technical upgrades, Charlotte development team had the answers

Because most of the issues were related to the electronic system, the device was completely redesigned from the ground up.


Until Sheila Fassler came to Enventys Partners looking for help with the Flosonix lice desiccation device, I had no idea how prevalent and how much of a problem head lice infestations can be.

The effects can be more serious than embarrassment and fear. The small, blood-sucking insects nest in the scalp and suck blood from the host human, causing itching that can lead to sores and scabs. When lice eggs are laid at the base of hair follicles, the sticky egg sacks can glue hair together and make it nearly impossible to comb.

Over-the-counter treatments at drugstores often provide only a temporary slowdown to lice and fail to eradicate them. So a small case of lice can easily slide into months of infestation.

Sheila and her team at Pediatric Hair Solutions—like Enventys Partners, based in Charlotte—own a number of lice clinics in the Southeast and have developed a two-step solution that has been proven to kill both active adult lice and their eggs.

The treatment starts with the Flosonix pretreatment solution, a non-toxic liquid applied to the scalp that suffocates and kills lice by clogging their respiratory system. Then patients come into the lice clinic, where technicians administer a 40-minute treatment with the Flosonix device that blows controlled-temperature warm air onto the scalp to dry out the lice eggs, causing them to crack and die.

Identifying deficiencies

The Flosonix team came to Enventys Partners with a lice desiccation (extreme drying) device that was capable of successful treatments, albeit with a few nagging issues.

The device was controlled with an Arduino, which had trouble operating for long periods in the heated environment and would periodically lose its programming. Because the air temperature at the output of the hose is crucial to the efficacy of the device, the team  wanted tighter control of air temperature at the output for more consistent treatments.

The user interface needed an upgrade from the mechanical dial it was designed with; the team also wanted the head to be more ergonomic for technicians. Another goal was to give the blower a brushless motor to cut down on particulates and maintenance.

Complete redesign

Because most of the issues were related to the electronic system, the device was completely redesigned from the ground up.

We replaced the Arduino with a Particle Photon WiFi-enabled controller, which gave Flosonix IoT capability. This allowed us to send performance data to a database to monitor its health and the ability to update the firmware remotely.

A new control circuit was designed for the brushless motor to allow for tighter temperature control of the air, and we added a touchscreen interface. The mechanical systems were also given a boost.

The form factor of the device stayed the same, but we designed a new head to distribute air more evenly to the scalp. We also made the hose and tips more ergonomic and easier to install.

Once the design was complete, 10 of the new spec units were built and distributed to clinics in the Carolinas, New York, and Indiana for testing.

After a year of field-testing the first 10 units, the team made a series of final design refinements before manufacturing.

A key issue was the weight of the unit. The initial device bodies were made from a large PVC tube that was thick and heavy. The body was redesigned to be a series of bent aluminum parts that were much lighter but still rigid.

The circuit was modified to have additional diagnostics and backup sensors to add more robustness in the field. The firmware was modified to allow over-the-air updates to the touchscreen. We also added a simple app to allow users to change the WiFi credentials on the Particle Photon inside the device.

After changes were verified with a final round of prototypes, the new Flosonix was ready for production.

Production success

The production of the Flosonix device is done at the Enventys Partners facility. The units were purposely designed for low-volume production, as the initial manufacturing quantities would be in the hundreds for the relatively large devices.

For this reason, many of the plastic parts were designed for 3D printing, including parts in the high-heat areas adjacent to the heater. Because these parts needed to be tough, heat resistant, highly aesthetic and sterilizable, it was a big challenge to find appropriate additive manufacturing equipment and materials.

Fortunately, Enventys Partners was able to team with Origin 3D printers for the job. Two of Origin’s “One” 3D printers were installed in the Flosonix manufacturing area; they run for more than 20 hours per day, using specially formulated materials from Henkel.

The printed parts were mated up to the rest of the mechanical and electrical sub-assemblies. The final assembly of the device was done in a secure area, with each device enduring more than an hour of rigorous quality-control testing to ensure proper performance before being shipped to end customers.

Flosonix units are now distributed to lice clinics around the country. Users are effusive about how easy the device is to use and its effectiveness.

The firmware that controls the device continues to be fine-tuned, with periodic updates pushed to devices in the field. A cellular-connected version is due to launch this year.