Samsung launches flagship Galaxy S5 smartphone

Samsung unveiled Monday its new flagship Galaxy S5 smartphone armed with a fingerprint scanner and a built-in heart rate sensor to defend its place as the world's industry leader.

Taking the limelight on the opening day of the world's biggest mobile fair in Barcelona, Spain, the South Korean giant simultaneously revealed a connected bracelet for health-concerned customers.

Samsung made about 30 percent of all smartphones sold in the world last year, nearly twice the share of archrival Apple, which traditionally skips the annual World Mobile Congress.

But Samsung, which announced its new devices on the sidelines of the February 24-27 event, is nevertheless scrambling for new revenue sources as competition in mature markets intensifies.

In a struggle to stand out from the competition, including a rising challenge from China, Samsung showed off the Galaxy S5 with a light sensor on the back that gives a heart rate reading when the user touches it with his or her fingertip.

Though the case is plastic, as with earlier versions of the Galaxy series of smartphones, it is water and dust proof, and has a leathery feel on the back.

The smartphone boasts a full high definition 5.1-inch screen and, catching up with Apple, the home button doubles up as a fingerprint reader to unlock the device or manage applications.

For people familiar with the desperation of a dying smartphone battery, the phone has an extreme battery-saving mode that turns the display black-and-white and retains just six key applications to keep the device going longer on the last remnants of its charge.

Global smartphone sales surged 42.3-percent to 968 million units last year, according to industry research group Gartner Inc.

But the growth was powered almost entirely by developing markets, disguising a slowdown in mature markets such as Western Europe and the United States, which are the most profitable.

As a result, mobile manufacturers are showing off a series of new smart devices to try to unlock new revenue streams.

The Samsung Fit bracelet follows that trend, with a curved touch-screen display and a heart-rate sensor to help give users feedback during exercise routines.

The previous day, Samsung unveiled an updated smart watch, the Gear 2, which also has sports tracking software and a heart rate monitor, plus a camera.

Samsung was one of the first major smartphone makers to produce a smart watch when it launched the Gear last September, but that version won only a lukewarm reception from critics who said it was unfashionable and clumsy.