Silver ink

Silver ink is prepared in the same manner, by substituting this metal, in leaf, for the gold.—Ure. 

Fig. 34.5. Capillary electrophoretic system with electrochemical detection. (A) Glass microchip, (B) separation channel, (C) injection channel, (D) pipette tip for buffer reservoir, (E) pipette tip for sample reservoir, (F) pipette tip for reservoir not used, (G) Plexiglass body, (H) buffer reservoir, (I) sample reservoir, (J) blocked (unused) reservoir, (K) detection reservoir, (L) screen-printed working-electrode strip, (M) screen-printed working electrode, (N) silver ink contact, (0) insulator, (P) tape (spacer), (Q) channel outlet, (R) counter electrode, (S) reference electrode, (T) high-voltage power electrodes, (U) plastic screw. For clarity, the chip, its holder, and the screen-printed electrode strip are separated, and dimensions are not in scale. Reprinted with permission from Ref. [112]. Copyright (1999) American Chemical Society.

Scheme 17.1. Schematic diagram of biosensor and wall-jet cell. (A) Screen-printed electrode front-view (1) silver ink acting as reference electrode, (2) graphite ink acting as working electrode successively modified with PB and (3) silver ink acting as counter electrode. (B) PB-modified screen-printed electrode side-view (1) polyester film as support for printing step, (2) graphite ink and (3) PB layer. (C) Wall-Jet flow cell side-view (1) inlet of the flow, (2) outlet, (3) cell made of Teflon and (4) glucose biosensor. (D) Wall-jet flow cell front-view (1) outlet, (2) inlet of the flow, (3) O-ring, (4) flow-cell and (5) glucose biosensor. Reprinted from Ref. [4] with permission from Elsevier.

In one report, a thick-film C electrode (by screen printing) was constructed. Carbon ink (10 p.m thick) was first printed on an alumina plate, and cured thermally. Then the silver ink (28 p,m thick) was printed and cured to partially overlap with and hence connect to the C layer. The thick-film C electrode was found to enhance the detection sensitivity, as compared to the thin-film amperometric detector [753]. 

Silver ink n. A printing ink whose principal pigment consists of aluminum powder. 

Near-field electrohydrodynamic jet printing with a tilted-outlet nozzle is used to obtain fine and highly conductive patterns of silver ink (31). Line widths that can be produced by near-field electrohydrodynamic jet printing are less than 6 pm. This is approximately twenty times smaller than that of conventional inkjet printing. 

Other successful electrochromic devices have been realized by Kelly et al. using polyaniline-impregnated fibres [79]. In situ electrochemical polymerization of polyaniline is used to bind poly aniline to a PET or viscose spacer fabric. The fabric is then impregnated with an electrolyte and sandwiched between two electrodes. For the bottom electrode, carbon black or silver ink can be printed directly on the fabric. Polyaniline colour changes from green to blue through oxidation—reduction processes. However, the lifetime of this structure is also short and does not exceed dozens of oxidation—reduction cycles. 

A bladder-fill system with the stainless steel stencil mounted and silver ink applied to the stencil. 

XINK Laboratories, another supplier, can offer lexographically printed RFID antennae using a proprietary silver ink which cures at ambient temperature. The company s materials are printable in a single pass on to a range of heat-sensitive substrates such as PET and paper as well as those used in pharmaceutical packaging for example. PolylC directly prints the RFID circuitry on to standard polyester foil using organic semiconductors and insulators to build up the necessary transistors. 

Polymeric piezoelectric films (PVDF) were used as substrate for cell growth. These thin films consisted of a 12 x 13 mm active area, printed with silver ink electrodes on both surfaces in a 15 x 40 mm die-cut piezoelectric polymer substrate, polarized along the thickness. In dynamic conditions the substrates were deformed by applying a 5 V current, at 1 Hz and 3 Hz for 15 min. 

Screen printing is used to print resist on foU and silver inks on polyester. Ink jet printing has been used to pattern resist, legend, and silver conductors. 

Merilampi, S., et al., 2010. Analysis of electrically conductive silver ink on stretchable substrates under tensile load. Microelectron. Rehab. 50 (12), 2001-2011. 

Aluminum Hydrate See Aluminum Oxide, Hydrated. Aluminum Ink See Silver Ink. 

Ag Migration. In the presence of water and an electric field, silver is anodically dissolved at its original location and moves toward the cathode where it is deposited. This migration phenomenon can lead to the growth of dendrites between adjacent electrodes and lower the surface insulation resistance (SIR) of the board. For many years, the short circuit due to Ag migration has been a nuisance to those using silver inks and similar materials. 

The SPCE assembly (Fig. lb) [25] consisted of a carbon paste working electrode, a silver ink pseudo-reference electrode, and a silver ink auxiliary electrode and was fabricated using a typical screen-printing equipment. The SPCE modified with carboxylated SWCNTs (SWCNTs/SPCE) was prepared as described in [35]. 

It is standard practice to cure the printed circuits in a drying oven or reflow-soldering oven. There is a direct relationship between dwell time and curing temperature. Low temperatures necessitate long curing times to permit the ink to cure. This is the method of choice for substrates with low thermal durability. The dwell times for silver inks, for example, can be anything from 15 minutes up to 2 hours. The relationship between dwell time and temperature is also reflected in electrical conductivity, which tends to increase with sinter temperature. 

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