The technology behind CORE - miniaturized thermal energy transfer sensors

Technology is the foundational stone of CORE, a non-invasive solution to monitor core body temperature. CORE uses a new type of thermal energy transfer sensor specifically designed by our parent company greenTEG in Switzerland.

Accurate and non-invasive tracking of core body temperature has proven to be a difficult combination but with the new thermal energy transfer sensor which features in CORE, we were able to overcome many of the hurdles that have long made this unobtainable. 

What is thermal energy transfer and why is it important?

As humans we really don't sense temperature, we sense thermal energy transfer.  For example, if you touch two different things such as a wooden object and a metal object on your table, they feel like they have different temperatures when in fact they will actually have the same temperature. What you are really sensing is energy transfer and the effect is that more energy is removed by the metal when you touch it than the wood. 


Thermal energy transfer is a well-known effect created by temperature differences in a given system. It always goes from the hot to the cold side of a material and requires a medium through which the heat is flowing. In our case, we are speaking about a solid medium, the human body, performing an activity in the open air. Heat goes either from the body to the surroundings (when the environment is colder than the body), or in the opposite way (when the body is colder than the environment). 

Hence, thermal energy transfer becomes a good way to understand how the heat goes in and out of the body. In both cases the body systems are working to keep the temperature stable, creating power in the process to either warm-up or cool down the whole system. 

This process is well-known for all the athletes: it takes a lot more energy to perform physical activities in cold or hot environments. We need to either create warmth in the body or cool it down through sweat. More energy needs more body effort. And more effort increases the physical demands on the athletes. When the body is regulating, a lot more energy used and as a result, the body needs more energy in total to achieve the same results.

Knowing how the process works helps the athletes improve their performance, especially during high-demand activities, such as endurance races. Not only can athletes train and optimize their activity, with the core body temperature in mind and a clear awareness of their thresholds and optimal range, but an athlete can also actively cool, for example, or reduce power or effort to avoid breaching their limits which would impact their performance. 

However, has not been an easy way to track thermal energy transfer in real-time. This is the gap that we at CORE want to fill in with our thermal energy transfer sensor.

How does a thermal energy transfer sensor work?

The technology behind CORE - miniaturized thermal energy transfer sensors

thermal energy transfer sensor is a device based on the Seebeck effect: when heat passes through the sensor, it generates a voltage signal proportional to the energy passing through. Tracking this signal means that the overall thermal energy transfer can be measured in real-time. 

The basics are simple: if we put a thermal energy transfer sensor on the skin, we can measure the energy going through it. The data extracted will help to understand the overall system, including the relationship between body temperature, heat transfer with the environment, and energy consumption. These three elements create a balance that preserves the health of the body.

Knowing this balance will likely help athletes to get more efficiency, using energy to create more power rather than keeping the overall system stable in terms of core body temperature. That means better training, better performance, and less risk of heat-strokes or system collapse.

With CORE we recognize that the core body temperature metrics mean that athletes will be able to get more insights to understand their body from a health aspect and of course can then utilize this to optimize effort and power... the end result is better sporting performance.

CORE’s innovative thermal energy transfer technology

Miniaturized energy transfer sensors - COREThis theoretical foundation opens the door to exciting prospects but there is still an elephant in the room... a fact that can't be overlooked.  Existing sensors are simply too big for a convenient, compact, and wearable device. The smallest sensor we have built to measure thermal energy transfer is the size of a small coin. Embedding this into a technology-filled smartwatch or creating a new product will result in an unreasonable large product or unit. 

To solve this issue of the sensor side, CORE has developed a proprietary technology that makes the difference. We use the greenTEG's core body temperature sensor which is a miniaturized sensor developed specifically to measure core body temperature and be able to fit into tiny devices. For the first time, energy transfer sensor capabilities can now fit into a compact and wearable unit. 

But that is not all. The sensor is the crucial part of CORE which makes it possible, but it relies on the expertise of our team to make a complete, seamless, and usable product. On the horizon, we have clinical testing, prototyping, and field testing ahead of us. But this is also a journey that will continue and will get better so we hope you come along for the ride.