The emergence of Internet of Things (IoT) has brought forth new opportunities by seamlessly integrating the physical world using computing, sensing, and wireless networks, transforming it into a cyber-physical system. An essential building block enabling an IoT is a sensing system. The use of "near-field communication (NFC)" has gained attention in recent years, as it enables low-power short-range sensing and wireless transfer of low content information. The NFC, however, is inapplicable in scenarios where the real-time high-resolution image or video of the object(s) needs to be sensed. The penetration of THz waves through many materials, which are impervious for visible light makes THz imaging akin to X-rays, except that THz radiation is non-ionizing and therefore not harmful to the object being imaged, especially living tissues. This special issue paper presents an overview of recent advances in the development of siliconbased mm-wave/THz imaging sensors for near-field IoT applications.