Membrane technologies electronic devices

Membranes fabricated using the MEMS technology are finding an increasing number of applications in sensors, actuators, and other sophisticated electronic device. However, the new area of application of MEMS is creating new materials demands that traditional silicon cannot fulfill [43]. Polymeric materials, also in this case, are the optimal solution for many applications. Microfabrication of polymeric films with specific transport properties, or micromembranes, already exists, and much work is in progress [44-50]. 

All books, reviews, and entries on CPs describe the potential applications. Chandrasekhar and others ° have reviewed in comprehensive fashion the applications of CPs, including batteries sensors electro-optic and optical devices microwave- and conductivity-based technologies electrochromic devices electrochemomechanical and chemomechanical devices corrosion protection semiconductor, lithography, and electrically related applications— photovoltaics, heterojunction, and photoelectrochemical cells capacitors electrolytic and electroless metal plating CP-based molecular electronic devices catalysis and delivery of drugs and chemicals membranes and LEDs. 

Another heuristic value of the proteinoids would be to use membranes and compare them to known electronic devices such as, for instance, tunnel diode or unijunction transistor. Some electronic properties of membranes made of proteinoids highly resemble the respective characteristics of these electronic devices. Here we closely approach the domain of the next step in computer technology. As yet predominantly, if not only, theoretical and conceptual attempts are described in the literature (e.g.. Ref. 57) including the patent literature. 

Polyfuel (USA), a spin-off of SRI International, is developing direct methanol fuel cells to replace Lithium ion batteries in wireless, handheld and portable devices, based on patented, proprietary technology. PolyFuel s membranes are based on hydrocarbon polymers, rather than perfluorinated and are considered to be best-in-class for portable direct methanol fuel cells (DMFC) designed for portable electronic devices such as laptops, PDAs or cell phones. 

These results have demonstrated that the biomimetic approach of copying the supramolecular principle of archaeal cell envelopes opens new possibilities for exploiting functional hpid membranes at meso- and macroscopic scales. Moreover, this technology has the potential to initiate a broad spectrum of developments in such areas as sensor technology, diagnostics, biotechnology, and electronic or optical devices. 

The final principles of back-pulse filter technology are the nature and properties of the GORE-TEX membrane. The membrane is composed of expanded polytetra-fluoroethylene, or e-PTFE. The membrane traces its roots to the invention of e-PTFE by Robert W. Gore in 1969. Since that time, e-PTFE has found application in many areas including medical devices, electronics, fabrics and fuel cells to name a few. In the filtration area, e-PTFE is used in the form of a membrane to capture and remove particles from both gaseous and liquid streams. 

Today, iontophoresis of drugs across skin or mucosal membranes is a non-invasive (needleless) method where the rate of delivery is primarily determined by the magnitude of the applied current, making patterned and on-demand delivery possible. Commercially available devices are typically bench-top systems with discrete patches connected to a power supply by electrical cables. However, due to recent innovations in electronic circuitry and battery technology, ionto-phoretic treatments can be administered with small, integrated patch-like systems. 

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