Abstract:We demonstrated a technique to control the placement of 6-nm-diameter CdSe and 5-nm-diameter CdSe/CdZnS colloidal quantum dots (QDs) through electron-beam lithography. This QD-placement technique resulted in an average of three QDs in each cluster, and 87% of the templated sites were occupied by at least one QD. These QD clusters could be in close proximity to one another, with a minimum separation of 12 nm.Photoluminescence measurements of the fabricated QD clusters showed intermittent photoluminescence, which indicates that the QDs were optically active after the fabrication process. This optimized top-down lithographic process is a step towards the integration of individual QDs in optoelectronic and nano-optical systems. Manuscript Preprint 3

Methods for patterning biomolecules on a substrate at the single molecule level have been studied as a route to sensors with single-molecular sensitivity or as a way to probe biological phenomena at the single-molecule level. However, the arrangement and orientation of single biomolecules on substrates has been less investigated. Here, the arrangement and orientation of two rod-like coiled-coil proteins, cortexillin and tropomyosin, around patterned gold nanostructures is examined. The high aspect ratio of the coiled coils makes it possible to study their orientations and to pursue a strategy of protein orientation via two-point attachment. The proteins are anchored to the surfaces using thiol groups, and the number of cysteine residues in tropomyosin is varied to test how this variation affects the structure and arrangement of the surface-attached proteins. Molecular dynamics studies are used to interpret the observed positional distributions. Based on initial studies of protein attachment to gold post structures, two 31-nm-long tropomyosin molecules are aligned between the two sidewalls of a trench with a width of 68 nm. Because the approach presented in this study uses one of twenty natural amino acids, this method provides a convenient way to pattern biomolecules on substrates using standard chemistry.

We model the conditions under which firms should enter the market with modular products that support multiple standards instead of an integral product that supports a single standard. Product modularity enables firms to broaden their portfolios and increase their chances of investing in the “right” technologies early in a technology cycle. Entry with integral products instead occurs later in the cycle. We test the model’s predictions on a sample of the Local Area Network industry entrants during the 1990s.

Managers are often faced with the need to choose among multiple satisficing options. We call this situation equifinal choice and argue how it opens an opportunity for managers to choose a new trajectory for their firm—an opportunity for strategic action. Although equifinal choice can exist in any environment, it becomes most consequential when uncertainty is high. Uncertainty weakens the adherence of organizational members to a superordinate goal and the plurality of goals leads political processes to guide the firm’s strategy. Extant view has identified random choice as an unbiased, fair, simple, and swift solution to the problem of equifinal choice. Random choice is also commonly used in machine learning and artificial intelligence systems. As organizations augment their decision making with these systems, there is a threat that they forego these strategic opportunities and randomly choose actions that fail to harness commitment and trust. In this Point of View article, we highlight the problem of equifinal choice, explain different ways it can be approached, and motivate why strategic choice can be valuable for organizations over and above defaulting to random choice.

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