<s>
A	O
foldable	B-Application
smartphone	I-Application
(	O
also	O
known	O
as	O
a	O
foldable	B-Application
phone	I-Application
or	O
simply	O
foldable	O
)	O
is	O
a	O
smartphone	B-Application
with	O
a	O
folding	O
form	O
factor	O
.	O
</s>
<s>
It	O
is	O
reminiscent	O
of	O
the	O
clamshell	O
(	O
or	O
"	O
flip	O
phone	O
"	O
)	O
design	O
of	O
many	O
earlier	O
feature	B-Device
phones	I-Device
.	O
</s>
<s>
Some	O
variants	O
of	O
the	O
concept	O
use	O
multiple	B-Device
touchscreen	B-Device
panels	O
on	O
a	O
hinge	O
,	O
while	O
other	O
designs	O
utilise	O
a	O
flexible	B-Application
display	I-Application
.	O
</s>
<s>
Concepts	O
of	O
such	O
devices	O
date	O
back	O
as	O
early	O
as	O
Nokia	O
's	O
"	O
Morph	O
"	O
concept	O
in	O
2008	O
,	O
and	O
a	O
concept	O
presented	O
by	O
Samsung	O
Electronics	O
in	O
2013	O
(	O
as	O
part	O
of	O
a	O
larger	O
set	O
of	O
concepts	O
utilizing	O
flexible	B-Application
OLED	B-Device
displays	I-Device
)	O
,	O
while	O
the	O
first	O
commercially	O
available	O
folding	O
smartphones	B-Application
with	O
OLED	B-Device
displays	I-Device
began	O
to	O
emerge	O
in	O
November	O
2018	O
.	O
</s>
<s>
Some	O
devices	O
may	O
fold	O
out	O
on	O
a	O
vertical	O
axis	O
to	O
into	O
a	O
wider	O
,	O
tablet-like	O
form	O
,	O
but	O
are	O
still	O
usable	O
in	O
a	O
smaller	O
,	O
folded	O
state	O
;	O
the	O
display	O
may	O
either	O
wrap	O
around	O
to	O
the	O
back	O
of	O
the	O
device	O
when	O
folded	O
(	O
as	O
with	O
the	O
Royole	B-Application
FlexPai	I-Application
and	O
Huawei	B-Application
Mate	I-Application
X	I-Application
)	O
,	O
or	O
use	O
a	O
booklet-like	O
design	O
where	O
the	O
larger	O
,	O
folded	O
screen	O
is	O
located	O
on	O
the	O
interior	O
,	O
and	O
a	O
screen	O
on	O
its	O
"	O
cover	O
"	O
allows	O
the	O
user	O
to	O
interact	O
with	O
the	O
device	O
without	O
opening	O
it	O
(	O
such	O
as	O
the	O
Samsung	B-Application
Galaxy	I-Application
Fold	I-Application
series	I-Application
)	O
.	O
</s>
<s>
Horizontally-folding	O
smartphones	B-Application
have	O
also	O
been	O
produced	O
,	O
typically	O
using	O
a	O
clamshell	O
form	O
factor	O
.	O
</s>
<s>
The	O
first	O
generation	O
of	O
commercially	O
released	O
foldable	B-Application
smartphones	I-Application
faced	O
concerns	O
over	O
their	O
durability	O
,	O
as	O
well	O
as	O
their	O
high	O
prices	O
.	O
</s>
<s>
In	O
2006	O
,	O
Polymer	O
Vision	O
showed	O
a	O
roll-able	O
concept	O
and	O
a	O
foldable	B-Application
smartphone	I-Application
,	O
the	O
Readius	O
(	O
zh	O
)	O
,	O
at	O
the	O
Mobile	O
World	O
Congress	O
(	O
MWC	O
)	O
which	O
also	O
serves	O
as	O
a	O
reader	O
.	O
</s>
<s>
In	O
2008	O
,	O
Nokia	O
presented	O
animated	O
concepts	O
of	O
a	O
flexible	B-Application
device	O
it	O
dubbed	O
"	O
Morph	O
"	O
,	O
which	O
had	O
a	O
tri-fold	O
design	O
that	O
could	O
be	O
bended	O
into	O
various	O
forms	O
,	O
such	O
as	O
a	O
large	O
unfolded	O
device	O
,	O
a	O
feature	O
phone-sized	O
unit	O
,	O
and	O
a	O
smart	B-Device
wristband	I-Device
.	O
</s>
<s>
In	O
a	O
2019	O
retrospective	O
on	O
the	O
concept	O
,	O
CNET	O
noted	O
that	O
Morph	O
could	O
be	O
considered	O
a	O
forerunner	O
to	O
the	O
first	O
wave	O
of	O
commercially	O
produced	O
folding	B-Application
phones	I-Application
,	O
as	O
well	O
as	O
a	O
showcase	O
of	O
future	O
possibilities	O
.	O
</s>
<s>
In	O
2011	O
,	O
Kyocera	O
released	O
a	O
dual-touchscreen	B-Device
Android	B-Application
smartphone	B-Application
known	O
as	O
the	O
Echo	B-Application
,	O
which	O
featured	O
a	O
pair	O
of	O
3.5-inch	O
touchscreens	B-Device
.	O
</s>
<s>
Unlike	O
the	O
Echo	B-Application
,	O
the	O
secondary	O
screen	O
could	O
be	O
folded	O
behind	O
the	O
phone	O
.	O
</s>
<s>
The	O
camera	O
rotated	O
with	O
the	O
screen	O
so	O
that	O
the	O
same	O
sensor	O
could	O
face	O
both	O
forward	O
and	O
rear	O
In	O
2017	O
,	O
ZTE	O
released	O
the	O
Axon	O
M	O
with	O
a	O
similar	O
hinge	O
to	O
the	O
Medias	O
W	O
.	O
ZTE	O
stated	O
that	O
the	O
more	O
powerful	O
hardware	O
of	O
modern	O
smartphones	B-Application
,	O
and	O
improvements	O
to	O
multitasking	O
and	O
tablet	B-Device
support	O
on	O
Android	B-Application
,	O
helped	O
to	O
improve	O
this	O
experience	O
.	O
</s>
<s>
The	O
development	O
of	O
thin	O
,	O
flexible	B-Application
OLED	B-Device
displays	I-Device
enabled	O
the	O
possibility	O
for	O
new	O
designs	O
and	O
form	O
factors	O
.	O
</s>
<s>
During	O
its	O
Consumer	O
Electronics	O
Show	O
keynote	O
in	O
2013	O
,	O
Samsung	O
presented	O
several	O
concepts	O
—	O
codenamed	O
Youm	O
-	O
for	O
smartphones	B-Application
incorporating	O
flexible	B-Application
displays	I-Application
.	O
</s>
<s>
One	O
such	O
concept	O
was	O
a	O
smartphone	B-Application
that	O
could	O
fold	O
outward	O
into	O
a	O
single	O
,	O
uninterrupted	O
tablet-sized	O
display	O
.	O
</s>
<s>
The	O
first	O
Youm	O
concept	O
to	O
make	O
it	O
to	O
a	O
production	O
model	O
was	O
the	O
Galaxy	B-Application
Note	I-Application
Edge	I-Application
—	O
a	O
phablet	B-Application
with	O
a	O
portion	O
of	O
the	O
screen	O
that	O
sloped	O
over	O
the	O
right-hand	O
bezel	O
.	O
</s>
<s>
Speculation	O
surrounding	O
the	O
development	O
of	O
folding	B-Application
phones	I-Application
using	O
OLED	B-Device
displays	I-Device
began	O
to	O
emerge	O
more	O
rapidly	O
in	O
2018	O
.	O
</s>
<s>
In	O
January	O
2018	O
,	O
it	O
was	O
reported	O
that	O
LG	O
Electronics	O
had	O
obtained	O
a	O
design	O
patent	O
for	O
a	O
folding	O
smartphone	B-Application
.	O
</s>
<s>
Later	O
in	O
June	O
,	O
it	O
was	O
reported	O
that	O
Microsoft	O
had	O
been	O
developing	O
a	O
similar	O
device	O
as	O
part	O
of	O
its	O
Surface	B-Device
line	O
,	O
codenamed	O
"	O
Andromeda	B-Application
"	O
(	O
itself	O
a	O
spiritual	O
successor	O
to	O
a	O
dual-screen	O
booklet	O
tablet	B-Device
prototype	O
Microsoft	O
had	O
been	O
exploring	O
in	O
the	O
late-2000s	O
known	O
as	O
Courier	B-Application
)	O
,	O
while	O
Samsung	O
was	O
also	O
said	O
to	O
be	O
developing	O
such	O
a	O
device	O
.	O
</s>
<s>
In	O
November	O
2018	O
,	O
the	O
Chinese	O
startup	O
Royole	O
released	O
the	O
first	O
commercially	O
available	O
foldable	B-Application
smartphone	I-Application
with	O
an	O
OLED	B-Device
display	I-Device
,	O
the	O
Royole	B-Application
Flexpai	I-Application
.	O
</s>
<s>
Later	O
that	O
month	O
at	O
its	O
developers	O
 '	O
conference	O
,	O
Samsung	O
officially	O
teased	O
a	O
prototype	O
of	O
its	O
folding	O
smartphone	B-Application
,	O
which	O
would	O
be	O
produced	O
"	O
in	O
the	O
coming	O
months	O
"	O
.	O
</s>
<s>
At	O
a	O
concurrent	O
developers	O
 '	O
summit	O
,	O
Android	B-Application
VP	O
of	O
engineering	O
Dave	O
Burke	O
stated	O
that	O
the	O
next	O
version	O
of	O
the	O
platform	O
would	O
provide	O
enhancements	O
and	O
guidance	O
relevant	O
to	O
folding	O
devices	O
,	O
leveraging	O
existing	O
features	O
.	O
</s>
<s>
In	O
January	O
2019	O
,	O
Xiaomi	O
CEO	O
Lin	O
Bin	O
published	O
a	O
video	O
on	O
Sina	B-Protocol
Weibo	I-Protocol
,	O
featuring	O
him	O
demonstrating	O
a	O
prototype	O
smartphone	B-Application
with	O
two	O
flaps	O
capable	O
of	O
being	O
folded	O
inward	O
.	O
</s>
<s>
Samsung	O
officially	O
unveiled	O
the	O
Galaxy	B-Application
Fold	I-Application
during	O
its	O
media	O
event	O
at	O
Mobile	O
World	O
Congress	O
in	O
February	O
2019	O
.	O
</s>
<s>
Alongside	O
the	O
Galaxy	B-Application
Fold	I-Application
,	O
the	O
convention	O
also	O
saw	O
other	O
foldable	B-Application
phones	I-Application
being	O
unveiled	O
or	O
teased	O
,	O
such	O
as	O
the	O
Huawei	B-Application
Mate	I-Application
X	I-Application
,	O
and	O
TCL	O
presenting	O
various	O
prototype	O
concepts	O
featuring	O
its	O
"	O
DragonHinge	O
"	O
technology	O
(	O
including	O
a	O
bracelet-styled	O
device	O
)	O
.	O
</s>
<s>
LG	O
did	O
not	O
unveil	O
a	O
folding	O
device	O
,	O
citing	O
a	O
desire	O
to	O
focus	O
more	O
on	O
re-gaining	O
market	O
share	O
in	O
the	O
smartphone	B-Application
market	O
.	O
</s>
<s>
It	O
did	O
,	O
however	O
,	O
unveil	O
a	O
"	O
Dual	O
Screen	O
"	O
case	O
accessory	O
for	O
its	O
LG	B-Application
V50	I-Application
smartphone	B-Application
—	O
a	O
folio-styled	O
case	O
containing	O
a	O
secondary	O
display	O
panel	O
inside	O
.	O
</s>
<s>
Other	O
companies	O
expressed	O
interest	O
in	O
the	O
concept	O
,	O
or	O
have	O
received	O
patents	O
on	O
designs	O
(	O
such	O
as	O
hinge	O
implementations	O
and	O
overall	O
designs	O
)	O
relating	O
to	O
foldable	B-Application
phones	I-Application
.	O
</s>
<s>
Motorola	O
Mobility	O
had	O
received	O
patents	O
for	O
a	O
horizontal	O
folding	O
smartphone	B-Application
reminiscent	O
of	O
clamshell	O
feature	B-Device
phones	I-Device
.	O
</s>
<s>
In	O
April	O
2019	O
,	O
the	O
impending	O
launch	O
of	O
the	O
Galaxy	B-Application
Fold	I-Application
was	O
met	O
with	O
quality	O
concerns	O
from	O
critics	O
,	O
after	O
widespread	O
reports	O
of	O
review	O
units	O
experiencing	O
varying	O
forms	O
of	O
display	O
failure	O
(	O
in	O
some	O
instances	O
caused	O
by	O
accidental	O
removal	O
of	O
a	O
plastic	O
layer	O
meant	O
to	O
protect	O
the	O
screen	O
in	O
lieu	O
of	O
glass	O
,	O
along	O
with	O
other	O
failures	O
)	O
.	O
</s>
<s>
Huawei	O
also	O
delayed	O
its	O
Huawei	B-Application
Mate	I-Application
X	I-Application
,	O
with	O
the	O
company	O
citing	O
its	O
desire	O
to	O
take	O
a	O
"	O
cautious	O
"	O
approach	O
due	O
to	O
the	O
Samsung	B-Application
Galaxy	I-Application
Fold	I-Application
.	O
</s>
<s>
In	O
November	O
2019	O
,	O
Motorola	O
unveiled	O
its	O
horizontal-folding	O
Razr	B-Application
—	O
inspired	O
by	O
its	O
former	O
Razr	B-Application
feature	I-Application
phone	I-Application
line	I-Application
released	O
on	O
6	O
February	O
2020	O
.	O
</s>
<s>
Samsung	O
also	O
announced	O
a	O
similar	O
device	O
known	O
as	O
the	O
Galaxy	B-Application
Z	I-Application
Flip	I-Application
.	O
</s>
<s>
Huawei	O
announced	O
the	O
Mate	O
Xs	O
on	O
24	O
February	O
2020	O
as	O
a	O
hardware	O
revision	O
of	O
the	O
original	O
Mate	B-Application
X	I-Application
;	O
it	O
was	O
released	O
in	O
"	O
global	O
markets	O
"	O
outside	O
China	O
in	O
March	O
2020	O
.	O
</s>
<s>
The	O
device	O
features	O
a	O
more	O
durable	O
display	O
,	O
improved	O
hinge	O
function	O
and	O
a	O
redesigned	O
cooling	O
system	O
,	O
as	O
well	O
as	O
the	O
newer	O
Kirin	O
990	O
5G	O
SoC	O
and	O
Android	B-Application
10	I-Application
with	O
EMUI	B-Operating_System
10	O
.	O
</s>
<s>
Samsung	O
later	O
revealed	O
the	O
Samsung	B-Application
Galaxy	I-Application
Z	I-Application
Fold	I-Application
2	I-Application
in	O
September	O
2020	O
.	O
</s>
<s>
On	O
25	O
February	O
2021	O
,	O
Huawei	O
released	O
the	O
Huawei	B-Application
Mate	I-Application
X2	I-Application
.	O
</s>
<s>
In	O
August	O
2021	O
,	O
the	O
Samsung	B-Application
Galaxy	I-Application
Z	I-Application
Fold	I-Application
3	I-Application
and	O
Samsung	B-Application
Galaxy	I-Application
Z	I-Application
Flip	I-Application
3	I-Application
were	O
released	O
.	O
</s>
<s>
On	O
11	O
April	O
2022	O
,	O
Vivo	O
introduced	O
the	O
Vivo	B-Application
X	I-Application
Fold	I-Application
.	O
</s>
<s>
The	O
Samsung	B-Application
Galaxy	I-Application
Z	I-Application
Fold	I-Application
4	I-Application
and	O
Samsung	B-Application
Galaxy	I-Application
Z	I-Application
Flip	I-Application
4	I-Application
were	O
announced	O
at	O
the	O
August	O
2022	O
edition	O
of	O
Galaxy	O
Unpacked	O
.	O
</s>
<s>
The	O
Galaxy	B-Application
Z	I-Application
Fold	I-Application
4	I-Application
was	O
released	O
on	O
25	O
August	O
2022	O
,	O
and	O
the	O
Galaxy	B-Application
Z	I-Application
Flip	I-Application
4	I-Application
was	O
released	O
on	O
26	O
August	O
2022	O
.	O
</s>
<s>
Motorola	O
Mobility	O
launched	O
the	O
Moto	O
Razr	B-Application
2022	O
on	O
11	O
August	O
2022	O
,	O
it	O
is	O
currently	O
only	O
available	O
to	O
the	O
Chinese	O
market	O
but	O
there	O
is	O
speculation	O
that	O
it	O
could	O
become	O
available	O
to	O
other	O
world	O
markets	O
at	O
a	O
later	O
date	O
.	O
</s>
<s>
Foldable	B-Application
smartphones	I-Application
typically	O
use	O
flexible	B-Application
,	O
plastic	B-Device
OLED	I-Device
displays	O
rather	O
than	O
glass	O
(	O
such	O
as	O
Corning	O
's	O
Gorilla	O
Glass	O
product	O
,	O
which	O
is	O
used	O
in	O
the	O
majority	O
of	O
mid	O
and	O
high-end	O
smartphones	B-Application
)	O
.	O
</s>
<s>
Plastic	O
displays	O
are	O
naturally	O
capable	O
of	O
sustaining	O
the	O
required	O
bend	O
radius	O
for	O
a	O
foldable	B-Application
smartphone	I-Application
,	O
but	O
they	O
are	O
more	O
susceptible	O
to	O
blemishes	O
and	O
scratches	O
than	O
traditional	O
glass	O
smartphone	B-Application
displays	O
.	O
</s>
<s>
Although	O
Corning	O
does	O
produce	O
a	O
flexible	B-Application
glass	O
product	O
known	O
as	O
Willow	O
Glass	O
,	O
the	O
company	O
states	O
that	O
its	O
manufacturing	O
process	O
requires	O
use	O
of	O
a	O
salt	O
solution	O
—	O
thus	O
making	O
it	O
unsuitable	O
for	O
electronic	O
displays	O
because	O
the	O
salt	O
can	O
damage	O
the	O
transistors	O
used	O
in	O
OLED	B-Device
panels	O
(	O
which	O
are	O
built	O
directly	O
on	O
the	O
panel	O
)	O
.	O
</s>
<s>
Nonetheless	O
,	O
the	O
company	O
stated	O
in	O
March	O
2019	O
that	O
it	O
was	O
in	O
the	O
process	O
of	O
developing	O
a	O
flexible	B-Application
glass	O
suitable	O
for	O
smartphones	B-Application
,	O
which	O
would	O
be	O
thick	O
and	O
have	O
a	O
bend	O
radius	O
.	O
</s>
<s>
Samsung	O
marketed	O
its	O
Galaxy	B-Application
Z	I-Application
Flip	I-Application
as	O
featuring	O
-thick	O
"	O
ultra-thin	O
glass	O
"	O
with	O
a	O
plastic	O
layer	O
similar	O
to	O
the	O
Galaxy	B-Application
Fold	I-Application
,	O
manufactured	O
by	O
Samsung	O
with	O
materials	O
from	O
Schott	O
AG	O
,	O
which	O
is	O
"	O
produced	O
using	O
an	O
intensifying	O
process	O
to	O
enhance	O
its	O
flexibility	O
and	O
durability	O
"	O
,	O
and	O
injected	O
with	O
a	O
"	O
special	O
material	O
up	O
to	O
an	O
undisclosed	O
depth	O
to	O
achieve	O
a	O
consistent	O
hardness	O
"	O
.	O
</s>
<s>
A	O
stress	O
test	O
by	O
YouTube	O
channel	O
JerryRigEverything	O
showed	O
the	O
screen	O
was	O
scratched	O
when	O
rubbed	O
with	O
a	O
pick	O
with	O
a	O
Mohs	O
rating	O
of	O
2	O
(	O
in	O
comparison	O
,	O
most	O
smartphones	B-Application
tested	O
by	O
the	O
channel	O
begin	O
to	O
experience	O
scratches	O
with	O
6	O
and	O
7-rated	O
picks	O
)	O
,	O
placing	O
its	O
durability	O
in	O
line	O
with	O
other	O
folding	B-Application
phones	I-Application
.	O
</s>
<s>
However	O
,	O
The	O
Verge	O
did	O
note	O
Samsung	O
's	O
statement	O
that	O
the	O
device	O
contained	O
a	O
protective	O
polymer	O
layer	O
similar	O
to	O
that	O
of	O
the	O
Galaxy	B-Application
Fold	I-Application
.	O
</s>
