site.btaBulgarian Entrepreneur Creates First Liquid Thermometer 

Bulgarian Entrepreneur Georgi Mutafchiev created an innovative liquid thermometer, the world's first product that shows changes in body temperature throughout the day, Mutafchiev told BTA.

The invention is called the TOM Thermochromic Application with Thermochromic Effect and contains specialized heat-sensitive pigments whose molecules are called thermochromic liquid crystals.

When the product is applied to the skin, an increase in body temperature leads to a reaction that changes the color of the pigments.  The sensitivity of the reaction is extremely high, which means that the color changes of the pigments occur at a strictly defined temperature.  Considering that the product is applied directly to human skin, the color change of the pigment directly corresponds to the changes in body temperature, and the influence of the ambient temperature is minimised, the product’s website explains. 

When applied on the skin, the ointment is black in colour, if the temperature is below 37C.  If the temperature is between 37.1-37.3C it turns purple, and a pink colour signals that the temperature  exceeds 37.4C.  The product’s main advantage is that it allows for the continuous monitoring of temperature for 24 hours after application, which no other product on the market offers. 

TOM is a great tool for preventive monitoring of changes in a person's body temperature, the website goes on to say, stressing that this is important, because an increase in body temperature, in the absence of other symptoms for a long period of time (over 10-14 days), may be due to chronic infections or systemic diseases. 

Mutafchiev said that he had the idea for the invention at the beginning of the COVID-19 pandemic. He was previously working on a different thermography project, using computer vision to determine and analyze temperature mutations on the human skin. When the pandemic began, Mutafchiev noticed a widespread issue with temperature-readers used to monitor people's temperature to determine if they had coronavirus symptoms - they often showed body temperatures of 32-35C due to the temperature differences outside and inside.  Mutafchiev began researching ways to monitor body temperature for a longer period of time. 

The entrepreneur explained that the creation of his invention was the result of cooperation with partners from the USA, who directed him to use thermochromic liquid crystals. Then the formula was developed by an outsourced company in Switzerland. The process of research and experimentation took about a year.  The product was then tested in a number of healthcare facilities to ensure that the application reports accurate results under different conditions. 

The fully developed TOM Thermochromic hit the market a year ago, in June 2021. It is produced in Bulgaria, but the thermochromic crystals are imported from the US. 

Mutafchiev noted that the next step is to expand the Bulgarian product internationally. The thermometer is currently exported to the Netherlands and Switzerland and in the process of expanding to the rest of the EU. Next would be USA, Turkey and South Africa. 

Mutafchiev is still in his early 20s, but has been part of several Sofia startups, in a team or co-founder role. TOM was his first solo project for developing his own product.  The young entrepreneur has already set his sights on other innovative projects such as  eco-friendly energy-efficient mobile homes.