Scientists have invented fabric solar cells that can turn any surface into a source of energy

MIT engineers have created ultralight solar cells made of fabric that can easily change any surface into a source of power. These lasting and adjustable solar cells that are as thin as a human hair and even more. They can be glued to a strong, lightweight fabric, thus they can be easily installed on a firm surface. They can produce energy in the form of wearable energy fabrics, or they can be carried and deployed to distant locations to assist in emergency situations.

The researchers said the cells weigh one-hundredth of conventional solar panels, produce 18 times more energy per kg, and are constructed from semiconductor inks with the use of printing processes that can be scaled up for large-scale production in the future.

Thanks to their thin and lightweight structure, the solar cells can be laminated onto different types of surfaces. For example, they could be built into sails to power boats at sea, or attached to tents and tarps that are used in disaster rescue, or used on the wings of drones to increase their flight range.

The standard silicon solar cells are fragile, which means they have to be wrapped in glass and a thick aluminium package, limiting where and how they can be deployed.

Six years ago, a research team at MIT made solar cells that were so light that they could sit on a soap bubble. One disadvantage was that these ultra-thin solar cells were manufactured using complex vacuum-based processes that are usually expensive and difficult to scale.

In their latest work, scientists have used nanomaterials, which are in the form of electronic inks that can be printed to make the solar cells. The researchers welded the structure of the solar cell using a slit-sealing device that applies layers of electronic materials to a ready-made loosening substrate about 3 microns thick. Using a screen print, the researchers applied an electrode to the structure, and then they stripped the printed module, which was about 15 microns thick, from the plastic substrate and created an ultralight solar device.

However, such thin, self-standing solar modules are difficult to handle and can easily break apart, making them difficult to deploy. In order to solve this, the team of researchers looked for a lightweight, flexible, and highly durable substrate to which solar cells could be attached. They found fabrics as the best solution because they provide mechanical strength and flexibility with almost no extra weight.

One of the optimal materials was a Dyneema, fabric that weighs 13 grams per square metre. The researchers glued solar modules to the fabric with UV-curable glue. This created an ultra-lightweight and mechanically strong solar structure.

When testing the device, the researchers discovered that it can generate 730 watts per kilogram of power when standing free, and about 370 W per kilogram when mounted on a Dyneema fabric. They also tested the resilience of the equipment and found out that even after more than 500 roll-ups and deployments of the fabric solar panel, the cells kept more than 90% of their original power generation capacity.