Design and manufacturing of a flexible heating element on textile for smarter working gloves

The overall project, funded by IRSST, focuses on the problem of cold intolerance in the workplace. Cold intolerance manifests itself primarily in the hands through pain, numbness, stiffness and color changes, and can also lead to loss of dexterity, discomfort and dysesthesia. This can lead to cessation of activities or career changes to sectors with more tolerable and warmer environments for the affected individuals. One effective means of prevention is the use of heated gloves.  The current range on the market, aimed primarily at the winter leisure and outdoor sports market, is not adapted to working conditions and the handling of vibrating tools. This is reflected, for example, in the deterioration of heating elements and connections between electronic components, which break down in fatigue under the effect of vibrations. In the absence of satisfactory solutions adapted to working conditions, the aim of this project is to develop and explore the potential of heated gloves, based on recent advances in printable electronics, to provide a technological solution to the problem of cold intolerance in the workplace.

One of the project's major stages therefore involves designing and manufacturing the heating element, as well as studying its functional properties. The aim of this stage is to determine the shape and positioning of the heating elements, as well as their electrical power, based on the target weather conditions. The design process therefore involves selecting the most suitable pattern to ensure uniform heating of the hands and fingers. Several patterns may be designed and tested; examples include S-curves and fractals, such as Peano curves. At the same time, the power and operating temperature of the printed circuit must be determined to ensure that the temperature does not exceed 43°C upon skin contact, thereby avoiding any risk of burns. Finally, with regard to the design, it will be possible to refer to existing simulation models or develop one if necessary.

In order to validate your design, the designed heating element will be printed using the printing parameters determined by a master's student (parallel sub-project). The printed heating element will then be subjected to electrical tests, optical measurements, and a test to assess the rigidity of the textile using the multidirectional deformation-free method. Finally, still in connection with the design of the heating element, one of the last elements to be designed will be the flexible connector to link the heating element to the PCB. The latter will also be developed in a parallel sub-project that you will be invited to supervise.

In summary, by participating in this project, your responsibilities will be to:

• Design and simulate heating element models (e.g., fractals and S-curves) to ensure uniform heat distribution.
• Determine the optimal energy requirements and validate the thermal safety limits (≤43°C when in contact with skin).
• Characterize the performance of the designed element using infrared thermal imaging and electrical and mechanical tests.
• Select, design and validate flexible connectors that are compatible with textiles and can connect the heating element to a PCB.
• Supervise and collaborate with Master's students responsible for the PCB and printing.
• Contribute to eco-design by exploring bio-based materials and ensuring the system's reparability.
   

In terms of expected results, the main deliverables of your project will be functional and durable printed heating elements, whose thermal and mechanical performance will have been validated. Finally, you will be expected to present your results at international conferences and publish in journals.