With the development of IoT, severe security threats and alerts associated with the use of smart devices have drawn increasing public attentions. The industry is expected to have 30 billion connected devices by 2020 which means that there will be 300 million troops waiting for mass destruction if only 1% of the devices are malicious or fake hardware. In this light, silicon Physical Unclonable Function (PUF) emerges as an inexpensive security primitive to overcome the device tagging problem by its radically different way of generating and processing secret keys in security hardware. Moreover, as unique and unclonable chip identifiers, chip designers can lock and unlock the circuit functionality to gain post-fabrication control of their intellectual property and clone detection. In this seminar, we will review the advancements of PUF over the past decade. Then, besides classical PUF structures and their applications, this seminar will address new breed of PUFs derived from emerging non-volatile memories and vision sensors.