Piezoelectric materials are defined by their ability to display a charge across surface in response mechanical strain, making them great for use sensing applications. Such applications include pressure sensors, medical devices, energy harvesting and structural health monitoring (SHM). SHM describes the process of using systematic approach identify damage engineering infrastructure. A method tha...

A CMOS image sensor that employs a vertically integrated double junction photodiode structure is presented. This allows colour imaging with only two, wider bandwidth, filters. The sensor uses a 184 x 154 6-transistor pixel array at a 9.6 μm pitch. Results of the device characterisation, and colour image reconstruction using the prototype sensor, are presented.

The optical structures of several active galactic nuclei (AGNs) have been studied using the Ðne guidance sensors (FGSs) on the Hubble Space Telescope (HST ). The FGSs are interferometric devices that can resolve structure on scales of 20 mas or less and hence have the potential to improve on the resolution attainable by HST Ïs cameras. The FGSs produce interferometric fringes known as S curves,...

In this paper, we propose a density control algorithm for wireless sensor networks to keep as few as possible sensors in the active state to achieve a connected coverage of a specific area of interest. Inactive sensors can turn off sensing modules to save energy. Unlike other algorithms, the proposed one does not rely on position information or ranging information of sensors. It just requires e...

Co irradiations have been carried out on test structures for the development of CMOS Active Pixel Sensors (APS) that can be used in a radiation environment. The basic mechanisms that may cause failure are presented. Ionization induced damage effects such as field leakage currents and dark current increase are discussed in detail. Two different approaches to overcome these problems are considere...

To address this issue, we propose an architecture for image sensor readout using a pipelined global shutter image sensor in which the readout is asynchronous and not scanned sequentially. Content aware pixels use a domino-like asynchronous readout and do not suffer from ambiguity during the decoding of the addresses. The analog data are then retrieved from the single pixels using the asynchrono...

Digital cameras are growing ever larger in silicon area and pixel count, which increases the occurance of defects at fabrication time, or dead pixels that develop over their lifetime. An Active Pixel Sensors self-correcting for most common faults is created by spliting the photodiode and readout transistors into two parallel portions with only a small area cost. Simulations show operation is th...

In this paper, we analyze the causes of the nonlinearity of a voltage-mode CMOS image sensor, including a theoretical derivation and a numerical simulation. A prototype chip designed in a 0.18 μm 1-poly 4-metal CMOS process technology is implemented to verify this analysis. The pixel array is 160 × 80 with a pitch of 15 μm, and it contains dozens of groups of pixels that have different design p...