This paper presents a design methodology emphasizing early and quick timing closure for high frequency microprocessor designs. This methodology was used to design a Gigahertz class PowerPC microprocessor with 19 million transistors. Characteristics of "Timing Closure by Design" are 1) logic partitioned on timing boundaries, 2) predictable control structures (PLAs), 3) static interfaces for dynamic circuits, 4) low skew clock distribution, 5) deterministic method of macro placement, 6) simplified timing analysis, and 7) refinement method of chip integration with early timing analysis.
We developed a batch-processed, flexible tactile sensor using carbon nanotube (CNT)-polymer composites. The fabricated sensor consists of a flexible substrate (polyimide), four flexible sensing parts (CNT-polymer composites) and a bump structure (SU-8). CNT-polymer composite was patterned on polyimide substrate through large area screen printing process. The proposed sensor structure has advantages in high sensitivity, mechanical flexibility and facile fabrication process. It showed outstanding piezoresistive characteristics in the pressure range up to 2 N.
We have developed a novel three dimensional tactile sensor based on vertically aligned carbon nanotubes. The carbon nanotubes were directly synthesized on silicon microstructures and these CNTs-on-microstructures were integrated to flexible polydimethylsiloxane layers. Each tactile sensor has four sensing parts and the direction of force can be detected by monitoring the increase or decrease of electrical resistance in each sensing part. High gauge factor up to 272 and fast response less than 10 ms have been experimentally verified from the presented tactile sensor. The deviated contact resistance change from the initial value was less than 3% after repeated force input of 15 mN for 180,000 cycles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.