From expanding screens to see-through displays: How tech giants are trying to jazz up their gadgets

See-through screens, phones that wrap around your wrist and expandable displays — these are all concept tech that gadget makers showed off this week, in a bid to stand out from competitors in a cut-throat hardware market.

At the world's largest mobile trade show, the Mobile World Congress in Barcelona, some of the biggest companies in the world showed off some unusual screen technology. While electronics firms have continually improved certain aspects of devices, such as battery life and cameras, the focus in recent years has shifted more toward innovations in displays, especially with the advent of foldable phones.

Screens have also become a focal point, given the increase in the amount of things on our devices.

Many of the MWC displays have also come from companies looking to create a buzz around their products and challenge the likes of Apple and Samsung.

"The sheer dominance of Apple and Samsung in connected devices means that other companies are having to go to great lengths to differentiate their products in an effort to turn consumers' heads," Ben Wood, chief analyst at CCS Insight, told CNBC.

"As a result we are seeing a proliferation of weird and wonderful new designs such as wrist worn phones, rollable screens, virtual 3D displays and more."

Here's some of the screen tech on display at MWC:

Tecno, a brand under the umbrella of Chinese firm Transsion that is now one of the biggest smartphone players in the world, showed off a handset with an expandable screen.

After pressing a button on the top of the device, the screen enlarges sideways.

Called the Tecno Phantom Ultimate, this is so far a concept device, and there has been no word on whether it will go on sale.

Motorola showed off a phone at MWC that can be bent in