Energy-harvesting E-textiles : Generating electricity from your every move

E-textiles are the criteria of smart textile which poses the way of integrating sensors, chips, and elements into the fiber or directly into the structures. Energy harvesting technologies have gained significant attention for capturing and converting ambient energy into usable electrical power. Energy harvesting capabilities can be integrated inside textiles, generating electricity from wearer’s movement. Our concern in this report will be the exact topic, even working in wet conditions. For e-textiles to function as comfortable and maintenance-free wearables, batteries should be replaced with energy-harvesting devices.

Piezoelectric sensors use the piezoelectric effect to measure changes in pressure, acceleration, temperature, or force by converting them to an electrical charge. The piezoelectric effect is the property of certain materials to generate an electric charge when they are mechanically stressed when an electric field is applied. Electronic textiles (e-textiles) are poised to play a key role in developing the Internet of Things. With recent developments in energy storage in the form of knitted and woven supercapacitors,  textiles are now being used as autonomous power sources.

Piezoelectric effects are now enabling textile garments to create energy by making the impact of a small amount of potential into a major one. Piezoelectric materials or polymers have the potential to show outstanding flexibility and tensile strength. Poly (vinylidene fluoride) (PVDF) offers the highest piezoelectric coefficient. The ability of PVDF to convert biomechanical energy to electrical power is being used in various applications.

PVDF with piezoelectric effects can be advanced and gratified through water usage. Melt-spun continuous fibers are attached with a core-sheath structure where one electrode is hidden inside the core. To complete the device, the second electrode, a conducting yarn, is wrapped around yarns of bicomponent microfibres by weaving. Thus small particles of piezoelectric polymers are spun into the inner segment of the textile.

The conducting core aids in the storage of generated electricity within the material. The efficiency of the conducting core determines the overall product quality. Another remarkable function of the conducting core is the flow of electricity throughout the textile product. The efficiency of electrical flow in a piezoelectrical structure should be maintained to maintain longevity over a long period.

Benefits of piezoelectric integration into textiles:

When integrated into textiles, they can harness energy from human movements, vibrations, or even natural elements like wind, rain, or friction. This can create a few amounts of electrical power generation. However, this energy is the main idea behind these innovations toward a greater goal. Piezoelectric materials can be seamlessly integrated into textile structures by weaving, and knitting, into fabrics. Thus they can easily be embedded into textile products without compromising their functionality.

Although integrating piezoelectric components and structure, the textile has the same drapability, flexibility, strength and comfort. No extra bulk has been added to the existing dimensions of the desired product. The flexibility enables the generation of electricity by the increased friction of body movement. The light weight is also noticeable in these textile products. Even after the implementation of piezoelectric components, the garment can adhere to its lightweight characteristics.

Energy-harvesting textiles based on piezoelectric materials can practically contribute to sustainable energy practices. Converting mechanical energy into electrical energy, piezoelectric textiles promote energy efficiency. They can potentially promote sustainability and environmental friendliness in various infrastructures. The energy generated is limited and can be used in certain projects or causes.

Energy harvesting piezoelectric material applications:

Energy-harvesting textiles can be incorporated into outdoor garments and sportswear, allowing users to generate electricity. Athletes can easily use these products with comfort and versatility. This harvested energy can charge small electronic devices like smartphones or GPS trackers for enhanced activity.

The piezoelectric textile can be applied to smart home appliances like bed covers, cushions, and sheets. The applicable places like light bulbs, desk lights, emergency bulbs etc, can also utilize these energies. Thus this research can empower future smart home building.

This exposure can also benefit the automotive industry. The industry can help with renewable energy by implementing the desired property into the seats and vehicle interiors so that the vibrations from the vehicle and temperature can create enough energy.

This fantastic invention can also be used in military equipment. This energy can enable extra flexibility for special equipment like sensors, commuters etc. The impact of the abrasion on the surface of textile products can be a good application for generating electricity.

Limitations of this energy harvesting process:

The overall energy density is a concern for these types of energy generation. Usually the pressure from raindrops, body deformation, strain, and heat can create a meager amount of dense energy in the desired product. Sometimes the environment is not in our favor at all. Raindrop dependant deformation needs a rainy day etc.

Exposure to moisture, difficulty in repeated electricity, usage of conductive core for a long time, heavily dependent functions etc can degrade the cloth over time. Thus the versatility of the product can be lessened after a calculative period.

The manufacturing of these special garments can be overly expensive. Typically in the recent industrial 4.0 approach, the core competencies of production are huge globally. The particular usage and limited demand for piezoelectric materials can be an extra burden on the industrial facility.

Still, the technique is somewhat in an early development and research stage. These products’ limited knowledge and applicability without a proper design and infrastructure can be a natural hazard to the weaving, knitting production process. In future textile applications, large-area woven piezoelectric fabrics may be used in the upholstery of passenger vehicles or as fillers in structural composites to convert ambient vibrations in combination with biomechanical movements from the user to electrical energy. Such an approach can create more energy simultaneously than the traditional approach.

While energy-collecting textiles provide intriguing potential for sustainable power generation, there are constraints to this development. Ongoing research and technology improvements can be made gradually to make this product available to the commercial market soon.