Energy-saving mobile phones are one concept everyone is keen on seeing, and Modelabs has come up with some clever mobile phone concept designs that deliver just that.

Modelabs, a customised design manufacturer, has developed a series of energy-saving mobile concepts. As well as the solar and kinetic energy-powered Yoyo phone , it has designed the U-Turn and Runaway models.

The U-Turn uses weird handle-shaped mobile uses opening and closing of the keypad-hiding display to recharge the internal battery. A two-character per-key Qwerty keyboard sits under the display for messaging and email apps.

Modelabs' Runaway is another concept phone, designed to be used for sports and other activities. It is powered by kinetic energy, using sporting movement to recharge batteries.

The Runaway is a modular design, with the main 'master' module carried by the user or on a piece of sporting equipment. Other elements such as the headphones are connected via Bluetooth. It also has activity measurement functions on-board, such as a heart monitor and tachometer.