
Clamshell design is a
form factor commonly used in the design of
electronic devices and other manufactured objects. It is inspired by the
morphology of the
clam
Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...
. The form factor has been applied to
handheld game consoles,
mobile phones (where it is often called a "flip phone"), and especially
laptop
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...
computers. Clamshell devices are usually made of two sections connected by a
hinge, each section containing either a
flat panel display or an
alphanumeric keyboard
The technology of computer keyboards includes many elements. Many different keyboard technologies have been developed for consumer demands and optimized for industrial applications. The standard full-size (100%) computer alphanumeric keyboard t ...
/
keypad, which can fold into contact together like a
bivalve shell
A bivalve shell is the enveloping exoskeleton or mollusc shell, shell of a bivalve mollusc, composed of two hinged halves or ''valve (mollusc), valves''. The two half-shells, called the "right valve" and "left valve", are joined by a ligament and ...
.
Generally speaking, the
interface components such as keys and
display are kept inside the closed clamshell, protecting them from damage and unintentional use while also making the device shorter or narrower so it is easier to carry around. In many cases, opening the clamshell offers more surface area than when the device is closed, allowing interface components to be larger and easier to use than on devices which do not flip open. A disadvantage of the clamshell design is the connecting hinge, which is prone to fatigue or failure.
The clamshell design is most popularly recognized in the context of mobile cellular phones. The term "flip phone" is used more frequently than "clamshell" in colloquial speech, especially when referring to a phone where the hinge is on the short edge – if the hinge is on a long edge, more akin to a laptop (e.g.,
Nokia Communicators), the device is more likely to be called just a "clamshell" rather than a flip phone. In the 1990s and early 2000s, what is now called "flip" phones were more commonly known as "folder" or "folding" phones, whereas "flip phone" referred to a now obsolete form factor most notably seen on the
Motorola MicroTAC.
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...
itself held the "Flip Phone"
trademark
A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...
until 2005.
Early examples in tech
A "flip phone" like communication device appears in chapter 3 of
''Armageddon 2419 A.D''., a science fiction novella by
Philip Francis Nowlan, which was first published in the August 1928 issue of the pulp magazine ''
Amazing Stories
''Amazing Stories'' is an American science fiction magazine launched in April 1926 by Hugo Gernsback's Experimenter Publishing. It was the first magazine devoted solely to science fiction. Science fiction stories had made regular appearance ...
'': "Alan took a compact packet about six inches square from a holster attached to her belt and handed it to Wilma. So far as I could see, it had no special receiver for the ear. Wilma merely threw back a lid, as though she was opening a book, and began to talk. The voice that came back from the machine was as audible as her own." Also from science fiction, ''
Star Trek: The Original Series'' featured a regular plot device called the "
Communicator" which influenced the development of early clamshell mobile phones such as the
Motorola MicroTAC and
StarTAC. The acronym "TAC" is an abbreviation of "Total Area Coverage" and was first used for the Motorola
DynaTAC.
Early examples of the form factor's use in electronics include the 1963
Brionvega
Brionvega is an Italian electronics company that is known for manufacturing futuristic television sets and audio equipment, its contributions to post-second world war technological and social advancement in Italian economic miracle, Italian in ...
TS 502 radio, the
Grillo telephone, which first appeared in Italy in the mid 1960s, and the
Soundbook portable radio cassette player, which was introduced in 1974 (the designer
Richard Sapper was responsible for all three of these, and was subsequently involved in the design of IBM computers). The form factor was first used for a portable computer in 1982 by the
laptop
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...
manufacturer
GRiD (who had the patents on the idea at the time) for their
Compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with No ...
model. In 1985, the
Ampere WS-1 laptop used a modern clamshell design.
File:Vintage Emerson Clamshell Travel Alarm Clock, AM-FM, Model 31P7C (8329706158).jpg, Emerson ''Cordless Travel Clock Radio'' (model 31P70), Japan (1960s)
File:20090704-1971 StarTrekTOSCommunicatorReplica.jpg, StarTrek ''Communicator'' (replica of late 1960s design)
File:Radioricevitore a transistor, portatile - Museo scienza tecnologia Milano 10074.jpg, Brionvega
Brionvega is an Italian electronics company that is known for manufacturing futuristic television sets and audio equipment, its contributions to post-second world war technological and social advancement in Italian economic miracle, Italian in ...
''TS 502'' radio, Museum of science and technology, Milan (1963)
File:Radioricevitore a transistor, portatile - Museo scienza tecnologia Milano 10074 07.jpg, (closed)
File:Telefono automatico a batteria centrale (BCA) - Museo scienza tecnologia Milano 08219 01.jpg, ''Grillo'' telephone, Museum of science and technology, Milan (1965)
File:Radioregistratore a musicassette, a transistor - Museo scienza tecnologia Milano 10088 dia.jpg, Brionvega
Brionvega is an Italian electronics company that is known for manufacturing futuristic television sets and audio equipment, its contributions to post-second world war technological and social advancement in Italian economic miracle, Italian in ...
''Soundbook'' portable radio cassette player, Museum of science and technology, Milan (1974)
File:GRiD Compass at National Air and Space Museum (2).jpg, GRiD ''Compass'', National Air and Space Museum
The National Air and Space Museum (NASM) of the Smithsonian Institution is a museum in Washington, D.C., in the United States, dedicated to history of aviation, human flight and space exploration.
Established in 1946 as the National Air Museum, ...
(1982)
File:Home computer portatile - Museo scienza tecnologia Milano 14618.jpg, IBM '' PC Convertible'' (model 5140) Museum of science and technology, Milan (1986)
In mobile phones

The clamshell design is known to have been applied to some
mobile phones. The popular contemporary term "flip phone" typically describes a clamshell cell phone where the upper part of the device folds out to reveal a display and keypad. Historically the term was different: "flip" earlier used to refer to a type of candybar phone with a folding cover, folding downwards to reveal a keypad – the modern definition for these are 'flip down'.
Such a design originated on
GTE landline phones, who held the trademark 'Flip Phone' until
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...
acquired it, a few years after releasing the
MicroTAC, the first cell phone in this form factor. Phones in this style were relatively common in the mid and late 1990s, other known examples being the
Ericsson T28. On the other hand, symmetrical clamshell designs that unfold upwards such as the
Motorola StarTAC were in earlier years variously referred to as "folder" type or style, or "folding" phones, before the term "flip phone" entered common usage during the 2000s to refer to these.
Clamshell phones also include other variations that are not typically referred to as "flip phone". The
Palm Treo 180, Motorola A760, and
Motorola MING are examples of clamshells where the exterior is a display cover, and the display is on the lower part – this was common on some
PDAs and PDA-style smartphones in the 2000s. Motorola also developed such a phone with a
touchscreen
A touchscreen (or touch screen) is a type of electronic visual display, display that can detect touch input from a user. It consists of both an input device (a touch panel) and an output device (a visual display). The touch panel is typically l ...
in 2008, the
Krave ZN4, but touch displays in this style were uncommon. The
Nokia Communicator series is an example of clamshell that look like a miniature
notebook computer. Also, some clamshells were made in an unconventional wider style, such as the fashion-oriented
Siemens Xelibri 6 and the
Alcatel OT-808 with a full QWERTY keyboard. In addition, some experimental clamshells look like the typical 'flip phone' but have additional mechanism and forms (like rotating displays), for example
Nokia N90, Samsung P400 and LG G7070.
Origins
The earliest notable clamshell phone was Motorola's StarTAC introduced in 1996. An iconic product, it was extremely compact and light for its time, and it flipped upwards to reveal a standard display and keypad on the lower part and a speakerphone on the upper. The StarTAC series was the first example of a fashionable mobile phone against the usual products of its time. For the rest of the decade, this 'flip up' clamshell style in mobile phones was mainly a product of Motorola only, and in 1999 the company released its next generation 'Vader' clamshell,
Motorola V series, which again achieved popularity and was even smaller than the StarTAC. It was the first flip phone (in the West) with the now-conventional design of a display in the upper part of the device and a keypad on the lower.
At the same time as Motorola's V series, the form factor took off in Asia: the StarTAC was extremely popular in South Korea, which led to
Samsung Electronics
Samsung Electronics Co., Ltd. (SEC; stylized as SΛMSUNG; ) is a South Korean multinational major appliance and consumer electronics corporation founded on 13 January 1969 and headquartered in Yeongtong District, Suwon, South Korea. It is curr ...
developing its first 'flip phone' clamshell, the SCH-800, released domestically in October 1998 to tremendous success. In 1999, Samsung released the silver-colored
A100 'Mini Folder' phone in South Korea to even greater success. Meanwhile in Japan,
NEC released the silver N501i flip phone in March 1999 for use with the new
i-mode mobile Internet service. Both Samsung and NEC popularised the flip phone in their respective countries. Cited benefits of the form factor compared to regular candybar phones were the ability to have a larger display in a smaller device, as well as not having the risk of buttons being accidentally pressed, and the subjective view that they were fashionable.
Popularity

After the millennium, clamshell-style cell phones experienced a boom globally, with Samsung especially being influential in this development whose line of silver flip phones were positively received as being stylish. The Samsung
SGH-A100 made its debut in Europe in 2000 and in the same year the company released locally the A200 'Dual Folder', which was the first clamshell phone with an external display – allowing users to see who is calling without opening the phone – a feature that would become industry standard. Marketed as "Blue-i" (referring to the blue backlit circular external display), the model was released in Asian markets in 2001 while other regions got the A300 model. Motorola released the
Motorola V60 in 2001 with a metallic body and an external display, a handset that became very popular in the US and was noted for looking luxurious.

The new style of flip phones were initially seen as solely fashion products, but by 2002 and 2003 they were dominating sales in Asia while being trendy elsewhere. The
Samsung SGH-T100 released in 2002 was the first flip phone with a color screen and it enjoyed global popularity. Motorola presented its first with a color display in the
T720. Samsung also released the first
3G (
UMTS
The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technolog ...
) flip phone in Europe, the SGH-Z100. Eventually many other manufacturers, mainly Asian (such as
LG,
Sharp and
Sanyo
is a former Japanese electronics manufacturer founded in 1947 by Toshio Iue, the brother-in-law of Kōnosuke Matsushita, the founder of Matsushita Electric Industrial, now known as Panasonic. Iue left Matsushita Electric to start his own bu ...
) as well as the likes of
Siemens were offering clamshell products globally.
Nokia
Nokia Corporation is a Finnish multinational corporation, multinational telecommunications industry, telecommunications, technology company, information technology, and consumer electronics corporation, originally established as a pulp mill in 1 ...
, the largest mobile phone manufacturer, had initially been reluctant to develop clamshell phones; it shipped its first such product in early 2004, the Nokia 7200, with unusual
textile
Textile is an Hyponymy and hypernymy, umbrella term that includes various Fiber, fiber-based materials, including fibers, yarns, Staple (textiles)#Filament fiber, filaments, Thread (yarn), threads, and different types of #Fabric, fabric. ...
covers. Nokia's products were more distinct with its rectangular corners and experimented with different styles as seen on the 7200,
2650 and 6170, although in 2005 the company released its first "Asian" influenced flip phone with rounded corners and a silver color, the
Nokia 6101.
Sony Ericsson also shipped its first flip phone, the Z600, in 2004, with the company mainly targeting women in its future flip phones ('Z' series).
The
Motorola V3 (RAZR) is the most iconic product during the peak of the flip phone era, combining the clamshell form factor with a sleek and thin, silver-colored body (although it was also released in pink and other colors), and a flat etched keypad. The lack of a protruding external antenna also helped its style (although it was not the first product with this distinction). The RAZR series was the best-selling phone in the United States for three years in a row (2005, 2006 and 2007). It was highly influential during the mid-2000s and a large number of rival manufacturers imitated its physical characteristics in their own new products.
In Japan, domestic flip phones during this time were uniquely advanced and has been associated with the
Galápagos syndrome. Flip phones were still ubiquitous here as of 2009, after it had already dropped in popularity in the West.
Flip smartphones
The Samsung SCH-i600 introduced in 2002 was one of the first
smartphones
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as mult ...
in a flip phone form factor; it ran on Microsoft's
Windows Smartphone 2002 software. Another early smartphone in this form factor was the
Kyocera
is a Japanese Multinational corporation, multinational ceramics and electronics manufacturer headquartered in Kyoto, Japan. It was founded as in 1959 by Kazuo Inamori and renamed in 1982. It manufactures industrial ceramics, solar power genera ...
7135 from 2003 which ran
Palm OS
Palm OS (also known as Garnet OS) is a discontinued mobile operating system initially developed by Palm, Inc., for personal digital assistants (PDAs) in 1996. Palm OS was designed for ease of use with a touchscreen-based graphical user interface. ...
and the
Motorola MPx200.
Panasonic
is a Japanese multinational electronics manufacturer, headquartered in Kadoma, Osaka, Kadoma, Japan. It was founded in 1918 as in Fukushima-ku, Osaka, Fukushima by Kōnosuke Matsushita. The company was incorporated in 1935 and renamed and c ...
introduced the first flip phone running
Symbian, the X700, in 2004.
Decline
Interest in flip phones declined during the late 2000s: this was first due to the growing popularity of
sliders, including 'slide-out
QWERTYs' that offered a full keyboard in combination with a wider, landscape-oriented display. The typically narrow body of the flip phone was a design constraint for incorporating a QWERTY. It was also affected by the growing popularity of
touchscreen
A touchscreen (or touch screen) is a type of electronic visual display, display that can detect touch input from a user. It consists of both an input device (a touch panel) and an output device (a visual display). The touch panel is typically l ...
-operated phones which started to be considered as more intuitive to use compared to traditional keypads. The flip phone – designed in mind with a display on the upper part and a keypad on the lower part – was impractical for use with a touch display (which could also incorporate QWERTY
virtual keyboards), so it fell out of favor when touchscreens became standard at the end of the decade.
Contemporary era

While flip phones had become largely obsolete in the 2010s, it was noticeably still relevant to a degree in Japan where various such products continued to be developed and offered by carriers such as
KDDI au and
NTT Docomo. Outside these territories, flip phones continued to be marketed as a
niche by some manufacturers (such as Alcatel, Doro, Kyocera, LG and Samsung), typically as cheap, basic
feature phones that remain popular among specialized audiences who prefer their simplicity or durability over smartphones.
In 2019, a new style of clamshell phones began to emerge using
rollable OLED displays, most often referred to as "
foldable smartphones". These also overlap with the slate form factor. Motorola unveiled the new
Motorola Razr in November 2019, the first major product in this style, which uses a foldable display and a clamshell design reminiscent of its
namesake line of feature phones. Samsung released the
Galaxy Z Flip, and the series has since expanded. Not all "foldable smartphones", however, are clamshell: the company's
Galaxy Z Fold, for example, uses a book-like vertical fold instead of a clamshell design.
Automotive

In automotive design, a clamshell bonnet or clamshell hood is a design where the engine cover also incorporates all or part of one of the
wings (fenders). It is sometimes found in a car with a separate chassis such as a
Triumph Herald or in cars based on a
spaceframe where the bodywork is lightweight and carries no significant loading, such as the
Ford GT40 and
Ferrari Enzo, where the whole rear end can be lifted to access the engine compartment and
suspension system. It is also sometimes seen in
unibody cars, albeit much more rarely – such as the
BMW Minis and
Alfa Romeo GTV.
It is also an informal name for General Motors full-size station wagons, manufactured from 1971 to 1976, that featured a complex, two-piece "disappearing" tailgate, officially known as the "Glide Away" tailgate.
Other uses

In addition to mobile phones; laptop computers and
subnotebooks; handheld game consoles such as the
Game Boy Advance SP
The Game Boy Advance SP (SP stands for "Special") is a 32-bit handheld game console made by Nintendo. It was released in Japan on February 14, 2003, and to international markets in March. This model is an upgraded version of the Game Boy Advance ...
,
Nintendo DS
The is a foldable handheld game console produced by Nintendo, released globally across 2004 and 2005. The DS, an initialism for "Developers' System" or "Dual Screen", introduced distinctive new features to handheld games: two LCD screens worki ...
, and
Nintendo 3DS (though these are less frequently described as "flip" or "clamshell"); objects such as
pocket watches, egg cartons, certain types of luggage,
waffle irons,
sandwich toasters,
krumkake irons, and the
George Foreman Grill are all examples a clamshell design.
Bookbinders build archival clamshell boxes called
Solander cases, in which valuable books or loose papers can be protected from light and dust.
The clamshell form factor is also commonly used in
product packaging.
See also
*
Dual-touchscreen
*
Foldable smartphone
*
Form factor (mobile phones)
*
History of mobile phones
*
Laptop
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...
*
Living hinge
References
External links
{{Mobile phones
Animals in culture
Design languages
Electronic design
Hinges
Industrial design
Telecommunications-related introductions in the 1960s
Mobile phones
History of mobile phones