strong intermolecular interactions and with reversible reduction and oxidation reactions characterized by means of optical, electrical, and morphological investigations on thin indigo fi lms. The OFETs and complementary-like inverters are among the best reported organic devices to date, in terms of mobility, voltage gain, symmetry, p- and n-type channel balance, low operating voltage window and high ON/OFF ratio. Moreover, these devices show that high performance electronics can be fabricated entirely from non-toxic, biodegradable, and extremely cheap materials.

Indigo - a natural pigment for high performance ambipolar organic field effect transistors and circuits

A wide variety of coating methods and materials are available for different coating applications with a common purpose of protecting a part or structure exposed to mechanical or chemical damage. A benefit of this protective function is to decrease manufacturing cost since fabrication of new parts is not needed. Available coating materials include hard and stiff metallic alloys, ceramics, bio-glasses, polymers, and engineered plastic materials, giving designers a variety freedom of choices for durable protection. To date, numerous processes such as physical/chemical vapor deposition, micro-arc oxidation, sol–gel, thermal spraying, and electrodeposition processes have been introduced and investigated. Although each of these processes provides advantages, there are always drawbacks limiting their application. However, there are many solutions to overcome deficiencies of coating techniques by using the benefits of each process in a multi-method coating. In this article, these coating methods are categorized, and compared. By developing more advanced coating techniques and materials it is possible to enhance the qualities of protection in the future.

On Coating Techniques for Surface Protection: A Review

The thermal degradation kinetics of polypropylene : Part III. Thermogravimetric analyses

A new family of electrothermally activated microactuators that can provide both large displacements and forces, are simple to fabricate, and are easily integrated with a large variety of microelectronic and microfluidic components are presented. The actuators use the high volumetric expansion of a sealed, surface micromachined patch of paraffin heated near its melting point to deform a sealing diaphragm. Two types of actuators have been fabricated using a simple three mask fabrication process. The first device structure consists of a 9 /spl mu/m thick circularly patterned paraffin layer ranging in diameter from 400 to 800 /spl mu/m all covered with a 4-/spl mu/m-thick metallized p-xylylene sealing diaphragm. All fabricated devices produced a 2.7-/spl mu/m-peak center deflection, consistent with a simple first order theory. The second actuator structure uses a constrained volume reservoir that magnifies the diaphragm deflection producing consistently 3.2 /spl mu/m center diaphragm deflection with a 3-/spl mu/m-thick paraffin actuation layer. Microactuators were constructed on both glass and silicon substrates. The actuators fabricated on glass substrates used between 50-200 mW of electrical power with response times ranging between 30-50 ms. The response time for silicon devices was much faster (3-5 ms) at the expense of a larger electrical power (500-2000 mW).

M. White

Papers

The structure and properties of evaporated polyethylene thin films