Apple Inc on Monday unveiled a robotic system called Liam to take apart junked iPhones and recover valuable materials that can be recycled, such as silver and tungsten. The move is an attempt to address criticism that Apple’s products, while sleek and seamless in design, are so tightly constructed that their components can be difficult to disassemble, refurbish and reuse. Liam, which has been under development for nearly three years, will initially focus on the…