National University of Singapore research team develops a new moisture-absorbing thin film insole

The new moisture-absorbing thin film insole can be the power supply for wearable devices

Perspiration is a natural process of body heat transmission. Body-moisture is mainly made up of water whose evaporation decreases the skin temperature to cool off human body.


National University of Singapore (NUS) research team develops a new moisture- absorbing thin film insole, effectively evaporating body moisture to cool off human body during the sports time. The thin film absorbs the body moisture to turn it into power supplied for wearable devices like watches.

The main components of the new thin film are two moisture- absorbing chemicals, cobalt chloride and ethanolamine. In addition to its strong moisture-absorption, the thin film of this type rapidly releases the moisture absorbed to recover itself to the original state, allowing itself to be used more than 100 times.


For the purpose of fully utilizing the moisture absorbed, NUS research team also devises a wearable energy-collection equipment composed of 8 EC (Electrochemical Cell) in which the thin film serves as electrolyte. With every moisture-absorbed EC producing 0.57 volt power, the equipment collects the total power supplied for a LED (Light Emitting Diode). The performance of thin film in power producing proves it practicable that wearable equipment without cells utilizes body moisture for power supply.


Considering traditional moisture-absorbing materials, such as zeolite and silica gel with a low rate of moisture absorption are block-shaped and solid, they are not suitable for body moisture absorption. In contrast, the new thin film developed by NUS research team absorbs moisture 14 times quicker than the traditional materials and increases the speed of moisture evaporation 6 times than normal. Besides, the thin film changes its color after the moisture absorption, from blue to purple, turning out pink. The color change can be an indicator of moisture absorption degree.


Breathable and waterproof PTFE thin film developed from the new moisture-absorbing thin film by NUS research team which demonstrates the successful application of PTFE thin film in armpit pad, shoe lining and insole, is resilient enough to be utilized in clothes. The prototype of the insole was made by 3D printing technology. The material used in this prototype is a mixture of soft polymer and hard polymer, providing sufficient support and shock resistance.


The NUS research team hopes to cooperate with enterprises to apply the new moisture-absorbing thin film to products.


Sources: 3xmaker