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Showing papers on "Biochip published in 1984"


Journal ArticleDOI
TL;DR: In this article, the authors describe the TCNQ-TTF (Tetracyanoquinodimethane) compound molecule as an electron acceptor (P-type) while tetrathiofulvolene (TTF) is an electron donor (N-type).
Abstract: different from that of my father's childhood. The world will then undoubtedly view the science of biological information processing as patently funOamental. But for the scientist the true golden age is now, just as golden days of biochemistry were its days of inception. Present-day digital computers (third generation) depend on the switching behaviour characteristic of PN silicon junctions ubjected to an electrical potential is fabricated by adding crystalline structure to electrons while N-type excess of electrons. To complex problems with ~ach has been to make smaller. This trend is asing popularity of such as microprocessors. in silicon technology has more complex software =ore computing resources. ers are expected to be lagnitude faster than ~rs while fifth-generation ,=cted to embody artificial such as pattern recognition. d-up still ; of are SIGBIO Newsletter page 4 exponential) would be the class of NP-complete problems. Of more immediate concern are the inherent limitations of current silicon technology. An example would be the time it takes for an electron to actually propagate through an electrical conductor as compared to the time taken by a silicon switching device to compute its function. Another example would be the fact that optical techniques currently used for etching circuits onto silicon wafers cannot be used for etching elements which are smaller than the shortest optical wavelength of around one micron {Baker. 1981). All approaches aimed at developing molecular switching devices which function analogously to silicon devices invariably start by attempting to synthesize a molecular PN junction. Such a device ~s the TCNQ-TTF compound molecule. Tetracyanoquinodimethane (TCNQ) is an electron acceptor (P-type) while tetrathiofulvolene (TTF) is an electron donor (N-type). Similar to the silicon PN junction, the TCNQ-TTF compound molecule allows current to flow in one direction while blocking current flow in the other direction. The TCNQ-TTF compound molecule was synthesized as far back as 1973 by researchers in organic superconductivity (Bechgaard and Jerome. 1982). Another synthetic organic material which has frequently been mentioned in regard to biochip technology is polyacetylene, (CH)x. The simple and fairly well-understood molecular structure of polyacetylene (Figure 1) makes it a strong candidate for use as a molecular filamentary conductor (Angler, 1982). In addition, recent experiments have demonstrated that polyacetylene can be doped to exhibit P-type and N-type behaviour in a manner analogous to silicon. Polyacetylene belongs to the increasingly popular class of conducting polymers. The interesting metallic properties exhibited by these polymers when appropriately …

50 citations


01 Feb 1984

7 citations