Synthesis and material and electronic properties of conjugated polymers

Conjugated polymers such as polyacetylene are semiconductors, and can be chemically doped to give very high values of conductivity (up to 150 000 S cm^–1). The semiconducting properties are due to delocalization of the electron system formed along the polymer chain, and this general class of materials shows many desirable semiconductor properties for electrical and optical applications. There are considerable challenges to find synthetic routes to allow processing of the polymer to the forms required for applications, and many of the recent important advances in the field are due to improvements in this area.     

Investigation of long term drift of an intraocular pressure sensor

Microsystem Technologies - “Zero drift” behavior of an optical intraocular pressure sensor is studied using an analytical model based on the deflection of a circular membrane. Results...     

Inside Front Cover: Efficient Top‐Gate,Ambipolar, Light‐Emitting Field‐Effect Transistors Based on a Green‐Light‐Emitting Polyfluorene (Adv. Mater. 20/2006)

The inside cover shows light emission from within the channel of an ambipolar field‐effect transistor based on the green‐light‐emitting conjugated polymer F8BT in a bottom contact/top gate structure, as reported by Sirringhaus and co‐workers on p. 2708. It visually demonstrates the formation of separate electron and hole accumulation layers in ambipolar transistors and radiative recombination of charge carriers where the two layers meet (schematic), which is controlled by the applied voltages.     

Making the gigabit IPsec VPN architecture secure

By placing the security processors directly in the data path to secure traffic without the aid of additional outside devices or software, the flow-through security device creates a virtual private network that maximizes network processing unit host offload with minimal system integration effort. A virtual private network uses the Internet protocol security (IPsec) framework to provide confidentiality, data integrity, and end point authentication. These features protect corporate data from being viewed or tampered with while in transit over the Internet. Additionally, the VPN supports data compression, which increases Internet performance between sites. Metropolitan area networks and storage area networks lead the trend toward gigabit Ethernet installations that seek to provide higher speed and better security. The decreasing cost of gigabit devices and their increasing availability in PCs are driving the use of gigabit MAN, while increasing data rates drive the use of gigabit SANs as the bit rate to hard-disk media approaches 1 gigabit per second.