Scientists make breakthrough in wearable “smart” fabrics. Made of...
Scientists make breakthrough in wearable “smart” fabrics. Made of electrospun polyvinylidene fluoride (PVDF) and nylon, silver nanowires (AgNWs) and polystyrene (PS), the new all-fibrous composite nanogenerator (AF-TENG) can be easily incorporated into clothing, allowing it to power small electronics through everyday movements.
Source: Elsevier

Smart textiles: breathable fabric to power small electronics

Scientists at University of Fukui have created a new triboelectric fabric that generates electricity from the movement of the body while remaining flexible and breathable.

Using the movement of a body to charge electronic devices such as phones may soon become a reality, thanks to the work done on triboelectric nanogenerators (TENGs). But most current TENGs are not breathable, making them uncomfortable to wear. Now, researchers have developed a multilayered TENG made from electrospun fibers, silver nanowires, and a polystyrene charge storage layer that not only has a high electrical performance, but also has superior wearability.

The triboelectric effect is a phenomenon where a charge is generated on two dissimilar materials when the materials are moved apart after being in contact with each other. Triboelectric nanogenerators use this effect to convert mechanical motion into electrical energy. The compactness of TENGs allows them to be used as wearable devices that can harness the motion of the body to power electronics. Being wearables, the emphasis is placed on the fabric properties (such as the comfort of the material) and the charge-carrying capacity of the nanogenerators. Generally, the triboelectric materials chosen for the nanogenerator should be safe, compatible with the human body (biocompatible), flexible and breathable while being able to maintain a high electrical output performance.

Among the many materials considered for TENGs, electrospun fibers are a promising candidate as they are lightweight, strong, and have desirable electrical properties. Electrospinning is a technique by which solutions of polymers are drawn into fibers using electrical charge. There are ongoing efforts to add metals to electrospun fibers to improve the electrostatic potential and charge-trapping capabilities. But this has led to compromises being made between the comfort and the output performance of the material.

Researchers from the University of Fukui, Japan and Nanjing University, China have developed an all-fibrous composite layer TENG (AF-TENG) that can easily be integrated with normal cloth. “With our work, we are aiming to provide a new point of view towards wearable energy harvesters and smart textiles,” says Dr Hiroaki Sakamoto, the corresponding author for the study.

The AF-TENG contains a triboelectric membrane made of two layers of electrospun fibers – one of a material called polyvinylidene fluoride (PVDF) and the other of a type of nylon. Silver nanowires cover these layers. The researchers further added a layer of electrospun polystyrene fibers between the silver nanowires and the triboelectric membrane.

The mechanical motion of the body while walking or running causes the triboelectric layers to gain a charge. This way, the mechanical energy is converted into electrical energy, which can be used to power electronic devices.

Normally, the charge buildup on the triboelectric surface is gradually lost or dissipated, reducing the surface charge density and the output performance of the nanogenerator. However, in this case, the added polystyrene membrane collects and traps the charge, retaining the surface charge density of the AF-TENG. The researchers used the AF-TENG to light up 126 commercial LEDs each rated at 0.06 Watt, demonstrating the feasibility of the nanogenerator. Moreover, according to Dr. Sakamoto, “The power generation device has flexibility and breathability since all components are composed of fiber materials. This device shows great potential in harvesting the static electricity from our clothes.”

While TENGs are currently limited to power low-powered devices such as LEDs and calculators, improvements to the wearability and output performance are integral steps towards future wearable technology.

The study was published in Nano Energy.

Subscribe to our newsletter

Related articles

Wash-and-wear biosensors

Wash-and-wear biosensors

A process turns clothing fabric into biosensors which measure a muscle’s electrical activity as it is worn.

‘Smart’ shirt keeps tabs on the heart

‘Smart’ shirt keeps tabs on the heart

A flexible carbon nanotube fibers can be incorporated into clothing to function as wearable health monitors.

Forget wearables: smart fabrics to monitor health

Forget wearables: smart fabrics to monitor health

Engineers have developed a method to transform existing cloth items into battery-free wearables resistant to laundry. These smart clothes are powered wirelessly through a flexible, silk-based coil sewn on the textile.

Smart textiles: a programmable digital fiber

Smart textiles: a programmable digital fiber

In a first, the digital fiber contains memory, temperature sensors, and a trained neural network program for inferring physical activity.

E-textiles made with new cellulose thread

E-textiles made with new cellulose thread

Researchers have developed a thread made of conductive cellulose, which offers practical possibilities for electronic textiles.

Sensor for smart textiles survives hammers

Sensor for smart textiles survives hammers

An ultra-sensitive, resilient strain sensor that can be embedded in textiles and soft robotic systems survived being tested by a washing machine and a car.

E-textiles: Dyeing process gives electronic properties

E-textiles: Dyeing process gives electronic properties

Scientists have shown how smart textiles can be produced in a comparatively easy way, thus opening up new use cases.

Robotic textiles could enable new mechanotherapy

Robotic textiles could enable new mechanotherapy

A new smart fabric that can be inflated and deflated by temperature-dependent liquid-vapor phase changes could enable a range of medical therapeutics.

High-tech clothing: Wearable health

High-tech clothing: Wearable health

Thanks to a variety of smart technologies, high-tech clothing today is capable of analyzing body functions or actively optimizing the microclimate.

Popular articles

Subscribe to Newsletter