Credit Juho Kim et al/APLUltra-thin solar cells are flexible enough to bend around small objects, such as the 1mm-thick edge of a glass slide, as shown here
Scientists in South Korea have made ultra-thin solar cells flexible enough to wrap around an average pencil - and the bendy panels could soon be used to could power fitness trackers, smart glasses or be woven into clothes to help power phones on the go.
The cells were then "cold welded" to an electrode by applying pressure at 170 degrees Celcius and melting a top layer of material called photoresist that acted as a temporary glue.
They performed bending tests and found the cells could wrap around a radius as small as 1.4 millimetres.
"Our photovoltaic is about 1 micrometre thick - much thinner than an average human hair," said researcher and engineer Jongho Lee.
"The thinner cells are less fragile under bending, but perform similarly or even slightly better," Lee added.
By transfer printing instead of etching, the new method developed by Lee and his colleagues may be used to make very flexible photovoltaics with a smaller amount of materials.