Apple Unveils Foldable Phone with Ultra-Thin Hair
Thickness Screen
The screens of foldable phones are a
triumph of materials science and microengineering.
·
Apple unveiled the iPhone Duo on 9 September 2026, its
first foldable smartphone, featuring a 7.6-inch glass display capable of
repeated bending.
·
Apple enters the foldable-phone market after
Google, Samsung and Motorola, which already offer foldable devices.
·
Apple CEO John Ternus said the
iPhone Duo would “redesign the experience” of using a foldable phone.
·
Ultra-thin glass is central to the technology: the
foldable glass layer is reportedly less than 30 micrometers
(µm) thick, compared with 50–100 µm for an average human hair.
·
Thinness makes glass flexible: reducing
thickness lowers the strain on the outer surface when the glass is curved,
allowing it to bend instead of breaking.
·
Materials-science principle: as
explained by Northwestern University professor John A. Rogers, thinner
materials are easier to bend—similar to the difference between a rigid piece of
wood and flexible paper.
·
Special glass formulations can
further improve flexibility. Research has shown that boron-trioxide-containing
glass can bend more easily than conventional glass when manufactured in
very thin layers.
·
Durable plastic is also used in the
display, providing an ultra-thin transparent layer designed to withstand hundreds
of thousands of folding cycles without clouding or warping.
·
Optically clear adhesives (OCA) bond the
multiple display layers. Their elastic, gel-like properties allow the layers to
shift slightly against each other during folding while remaining firmly
bonded.
·
Overall significance: Foldable
displays are the result of multiple advances in materials science and
microengineering, rather than a single technological breakthrough.
·
Apple's entry could strengthen competition in
the premium foldable-smartphone market and potentially accelerate adoption of
foldable devices.
Apple
on Wednesday (09.09.2026) unveiled the iPhone Duo, its first foldable
smartphone with a 7.6-inch glass screen that is capable of bending countless
times without breaking.
The
Duo is not the first foldable phone; Google, Samsung and Motorola have all
released devices with displays that bend. But in his pitch for the Duo, Apple’s
new chief executive, John Ternus, said the company’s latest offering “will
redesign the experience of using a foldable phone.”
The
screens of foldable phones are a triumph of materials science and
microengineering. No single breakthrough or industrial secret makes them
possible; rather, a series of complementary feats makes a display flexible
enough to bend many thousands of times without snapping yet strong enough to
survive drops and other abuse.
Glass
— the brittle, breakable kind — is what scientists call an “amorphous solid.”
It looks and acts like a solid, but glass atoms are actually frozen in a
liquid-like state. Everyday glass shatters when bent because those atoms lie in
a rigid matrix that, when thick, leads to extreme tension on the outer edge of
the curved surface.
But
glass becomes flexible if it’s thin. The average human hair is between 50 and
100 micrometers thick. The super-thin layer of glass
in a foldable iPhone is reportedly less than 30 micrometers
thick, or much finer than a human hair. At this step of miniaturization, the
strain on the outer edge becomes so low that the glass tends to curve rather
than break.
“The
thickness of a material determines its stiffness toward bending,” said John A.
Rogers, a professor of materials science and engineering at Northwestern
University. “If you make something very thin, it becomes easier to bend.”
Dr.
Rogers compared breakable and bendable glass to wood and paper. “If you think
about a piece of wood, it’s not very bendable,” he said. “But a sheet of paper,
which is also wood, is flexible because it’s much thinner. The same applies to
glass.”
In
addition to making glass thinner, chemists found that alternative glass
formulas could enhance the flexibility. Everyday glass is made of silicon
dioxide, which comes from melted sand. But boron trioxide, used mainly in
laboratory glassware that expands and contracts very little when heated and
cooled, has an atomic matrix that’s amorphous rather than rigid and
crystalline. Lab testing showed that, when thin, it bent more easily than
regular glass.
Another
extremely thin layer in a foldable screen is made of ultra-durable, highly
transparent plastic that’s engineered to endure hundreds of thousands of fold
cycles without clouding or warping.
Finally,
the many layers of a foldable screen are bonded together with what the industry
calls optically clear adhesives. Viscous and elastic, they act like a gel,
holding the layers together firmly but under the stress of a bend still allow
the layers to glide past each other.