# Thermochromic Yams' Application in Fever Detection for Young Children
###### Abstract  
The existing literature emphasizes the significance of and needs for developing body temperature monitoring devices that can consistently and discreetly assess the temperatures of young children. Such products could offer a method to check children's body temperature and alleviate parents' concerns over fever. However, research gaps and challenges exist in preserving material flexibility, conducting tests in a controlled setting that mimics body temperature, and investigating consumer perceptions of this type of functional textile product. Therefore, this research aimed to investigate functional textiles using thermochromic yams for young children's body temperature detection, particularly focusing on testing prototypes in a controlled environment and empirically investigating target consumers' perceptions of such products. Experimental prototype testing and a consumer survey were conducted in this study. The findings validate the practicality and market potential of such products. We also proposed alternative mediums for implementing the functional yarn and recommendations for developing these products based on target consumers' concerns and suggestions. This research helped identify potential economic development possibilities for functional textiles. functional textiles; thermochromic yams; young children; knitting; fever detection +
Footnote †: journal: Medical  
fever can heighten parents' physical and mental strain, leading to frequent temperature monitoring, anxiety, and sleep disturbances [11]. Therefore, researchers have been exploring textile-based solutions for temperature measurement that track body temperature continuously and unobtrusively [3]. The current predominant methods for monitoring temperature in smart textiles rely on traditional sensors such as thermo-elements, thermistors, and semiconductor sensors [5]. Traditional sensors on clothing are attached to the fabric rather than integrated into it, leading to substantial discomfort for users and skin irritation due to their rigidity [6]. Other challenges of traditional sensors in smart textile solutions for monitoring temperature include battery size, energy suitability, and washability. Some require removing the electronic components before washing [6]. Alternatively, researchers have been exploring functional textiles to detect body temperature changes, including thermochromic materials. Thermochromism is the reversible alteration in a compound's colour triggered by a temperature change, with the colour shift being obvious, sometimes dramatic, and happening within a narrow temperature range [12]. Thermochromism occurs due to various mechanisms based on the compound's molecular structure. The thermochromic mechanism can be categorized into three main groups: change in crystal structure, stereoisomerism, and molecular rearrangement [13]. To be used in textiles to detect body temperature, the component must (1) have a reversible and solid (or encapsulated) system that is appropriate for dyeing and printing, (2) display a distinct colour change within a narrow temperature range, usually from low ambient temperatures to body temperature, and (3) be cost-effective [14; 15]. These criteria make the molecular rearrangement mechanism, where temperature changes lead to a molecular rearrangement in a compound, causing an increase in conjugation within the molecule and the creation of a new chromophore, resulting in a colour change, the most achievable option [13]. However, thermochromic materials cannot dye the fibre directly due to their lack of affinity with it, necessitating microencapsulation [16]. [PERSON] et al. [17] applied thermochromic pigments to sportswear to visually spot muscle fatigue by observing colour changes in the garment as the skin temperature rises. A thermal manikin set in a controlled environment validated the pigment colour change. The manikin simulated the average skin temperature according to ISO standards and replicated a high skin temperature.