Purpose -This paper details the derivation of the mathematical formulae of a novel system for designing and fabricating tissue engineering (TE) scaffolds. Design/methodology/approach -This work combines the unique capability of rapid prototyping (RP) techniques with computer-aided design (CAD) and imaging software to design and fabricate customised scaffolds that are not only consistent in microstructure but also readily reproducible. The prototype system, called the computer-aided system for tissue scaffolds (CASTS), has a parametric library of design units which can be assembled into scaffold structures through an in-house algorithm. An additional module, the slicing routine, has also been added to improve the functionality of the system. To validate the system, scaffolds designed were fabricated using a powder-based RP technique called selective laser sintering (SLS). Findings -It is shown that the CASTS can be used to exploit CAD and medical imaging techniques together with RP systems to produce viable scaffolds that can be customised for various applications to suit the needs of individual patients. Research limitations/implications -Further research is being done to examine the internal microstructure of the scaffolds and to determine the mechanical properties, as well as to study the inter-relationship between cell proliferation and the pore shapes of the scaffolds. Originality/value -The crucial role of scaffolds in TE has long been recognised. Successful TE scaffolds should have controllable characteristics such as pore size, porosity, and surface area to volume ratio as well as interconnectivity within the scaffolds. Much work has been carried out to produce such TE scaffolds with varying degrees of success. One major drawback is that the resultant TE scaffolds are not readily reproducible. The potential of CASTS lies in its ability to design and fabricate scaffolds with varying properties through the use of different unit cells and biomaterials to suit different applications.

This work reports on the energy level alignment and charge transfer in organized assemblies of CdTe and CdSe nanoparticles (NPs), for both electrochemical systems and in solid-state photovoltaic devices. This work shows how control over the energy level alignment, by manipulation of the size and surface ligands of the CdTe and CdSe NPs, can be combined with control over the NPs spatial arrangement, either by sequential self-assembly onto a Au working electrode of an electrochemical cell or spin-coating onto an ITO substrate of a photovoltaic device, to facilitate photoinduced charge separation (photocurrent). By properly arranging the spatial and energetic hierarchy of the assemblies, the charge transfer direction and its efficiency can be optimized.

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Indium‐doped ZnO (IZO) films with various indium contents were deposited by sol–gel process for application in organic solar cells (OSCs). X‐ray photoelectron spectroscopy (XPS) spectrum verified that indium is incorporated in the ZnO films. All films showed polycrystalline nature with a hexagonal wurtzite structure of ZnO. The resistivity of the films initially decreases yet increases again with higher doping. The lowest resistivity of 5.54 × 10−1 Ω‐cm was obtained at 1 at.% indium‐doped film. The optical transmittance of all films is above 80% in visible range and blue shift in absorption edge was observed upon indium doping. The humidity level influences surface morphology, electrical, and optical properties of the doped films due to the strong moisture absorption nature of indium doping precursor. The performance of inverted OSC employing 1 at.% IZO as a buffer layer is higher than that of cell using un‐doped ZnO, which can be attributed to the higher optical transmittance and lower resistivity of doped film.

This work reports on the use of an internal electrostatic field to facilitate charge separation at inorganic-organic interfaces, analogous to those in hybrid solar cells. Systematic charge transfer studies show that the donor-acceptor charge transfer rate is highly sensitive to the direction of the internal electric field.