From vehicles to architectural lighting
VTT Technical Research Centre of Finland develops novel LED light sources based on large, flexible and transparent substrates in collaboration with the Finnish companies Flexbright and Lighting Design Collective. An easy-to-customise LED foil suitable for mass production enables the introduction of the large area lighting and display technologies to applications such as vehicles, greenhouses, shopping centres and architectural lighting.
The three-year European project Delphi4LED develops design and simulation tools for LED structures to better meet the needs of the rapidly evolving lighting industry and end users.
Heat management is a key factor dictating the performance and reliability of LED lighting solutions. The operation of LED components is also affected by their electrical and optical characteristics. Combining all of these properties is difficult using the existing design tools.
In Delphi4LED project new simulation models are being developed to consider the above factors in a simplified form. This saves on computing capacity, enabling a more comprehensive design than is currently possible.
Elaborated measurements are performed to produce a standardised electronic datasheet of the LEDs, which is then fed into a modelling software. This makes the design process more efficient and reduces the number of design errors, enabling the faster introduction of the products on the market, with higher quality and at a lower cost than before.
A Finnish consortium coordinated by VTT Technical Research Centre of Finland is applying the results of the Delphi4LED project to the development of LED luminaires based on transparent large-area foil. These kinds of novel structures enable the implementation of thin, flexible light source for lighting and display applications. For example, a multi-coloured video screen can be integrated between planar or curved glass surfaces.
NIMS developed new display sheets that can be cut into any shape with scissors.
A research group led by Masayoshi Higuchi, the leader of the Electronic Functional Macromolecules Group, Research Center for Functional Materials, NIMS, developed new display sheets that can be cut into any shape with scissors. As you can cut this display into any shape you like, and attach it on the surfaces of things that has complex shapes such as clothing and buildings, the display is expected to meet diverse display needs, which cannot be achieved by conventional display technologies.
Common displays (including LCD and OEL) that are capable of showing letters and images are equipped in most of the electronic devices we use in our everyday life. Also, there are increase in demand for displays that can present information in a variety of forms, such as digital signage and wearable devices. However, it is impossible to cut these conventional displays into various shapes because it is necessary to seal the contents of both LCDs and OELs, for example, as the LCDs contain liquid and OELs are susceptible to water, oxygen and other impurities. Moreover, since these displays require continuous power supply to maintain their functions, they must be connected with a power source or a drive. Due to these requirements, it had been difficult to develop cuttable displays using existing technologies.
The research group developed display sheets that can be cut into any shape with scissors, using a polymer with electrochromic properties (organic/metal hybrid polymer). This polymer can be sprayed onto a flexible substrate to form a coating layer stable against moisture and oxygen. In addition, the new display requires only a few seconds of electrical input to switch visual information, and the display will last even after power supply is discontinued. Accordingly, we successfully developed a sheet type display device capable of functioning while being detached from a power source and after being cut into a shape.