The possibility of direct selective surface activation by photodeposition of autocatalytic Cu particles on photosensitive TiO2 substrates in an alkaline electroless copper solution has been investigated. The nucleation and growth of particles were characterized by transmission electron microscopy (TEM). Ex situ high resolution TEM and in situ extendedx-ray absorption fine structure (EXAFS) spectroscopy were used to determine the oxidation state of photodeposited particles on thin polycrystalline TiO2 films and suspended TiO2 powders, respectively. It is shown that in the initial stages of photodeposition small (<3 nm) noncatalytic Cu20 particles are formed. Electroactive Cu particles are only observed at relatively long illumination times and/or high light intensities. These results are explained with a model of the illuminated TiO2 crystallite/electrolyte interface, which considers simple redox reactions involving transfer of TiO2 photoelectrons to energy levels of the couples between complexed Cu 2+ ions, Cu20 and Cu. From this it is concluded that under illumination Cu particles are only formed if deposition of Cu20 is limited by either mass transport of complexed Cu 2+ ions or kinetic factors.In the last few years patterned electroless metal deposition has gained increasing attention for potential application in the fabrication of microelectronic devices (1-5). Basically, electroless metal deposition involves a heterogeneous catalytic electron-transfer reaction, in which electrons are transferred from a reducing agent to metal ions. It can be carried out selectively on patterned electroactive areas on the substrate, since deposition is autocatalytic and requires an electrocatalytic surface to start. In most cases, the active areas are obtained by the application of electrocatalytic metal nuclei on the substrate, for example by photoselective activation procedures (6, 7). A disadvantage of this procedure is that metallization involves at least two steps: activation and electroless metal deposition. Furthermore, reducible species, e.g., adsorbedPd ions, may be left behind at undesirable places on the substrate after the activation step. When these are reduced to electrocatalytic species in the electroless solution, the latter may cause uncontrolled, nonselective electroless metal deposition. Therefore, it seemed worthwhile to study the possibility of direct selective surface activation in an electroless solution.In the work described in this paper, which is a continuation of earlier reports on different aspects of the initiation of electroless metal deposition (8-10), direct laser-induced copper deposition from an electroless copper solution on TiO2 substrates is investigated. It was exPected that photochemically deposited metallic Cu nuclei from an electroless solution on photosensitive TiO2 films would show autocatalytic behavior. This means that prenucleated areas on the TiO2 film should be intensified by subsequent electroless copper deposition in the dark. Preliminary experiments, however, showed that this...

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Most laparoscopic instrument development is technology-driven. In this approach to instrument design, the physical and emotional comfort of the users is not always considered, leading to a user-unfriendly product design. One reason for this flaw in the design of instruments is the lack of standards in this field. Our study presents a new set of design guidelines for one type of instruments used in laparoscopic surgery, namely 'instruments for intensely manipulating tissue'. These guidelines cover technical comfort, user friendliness and the emotional comfort of the user-group. In situ and pelvi-trainer tests were performed to illustrate the poor performance of the instruments and equipment that are currently being used. The three comfort areas were studied both objectively and subjectively, and guidelines for instrument function groups were set up and validated. New instruments are designed and tested according to these new guidelines. The results of our studies show that our new instruments score better on all three levels than currently available instruments. Therefore, our conclusion is that products should not be designed exclusively according to technical guidelines and new technologies; the physical, cognitive and emotional comfort of the users should also be considered, to create an optimal human-product interaction.