A flexible electrochromic active matrix addressed display, including 8 × 8 pixels, is demonstrated by using solution processing based on standard printing coating manufacturing techniques. Each organic electrochromic display (OECD) pixel its corresponding organic electrochemical transistor (OECT) are located on different sides of the flexible PET substrate. Electronic vias generated through the plastic substrate connects each OECD pixel with one addressing OECT. When comparing this display with actively addressed OECDs with all its components located on the same side, the present approach based on this electronic via substrate provides an enhanced pixel resolution a relatively more simplified manufacturing process.
The mechanism of thermal actuation for poly(vinylidene fluoride) (PVDF) and polyethylene (PE) tie molecules has been investigated using molecular dynamics simulations. Tie molecules are found in semicrystalline polymers and are polymer chains that link two (or more) crystalline lamellae, allowing for the transfer of force between these regions. A novel simulation technique has been developed to enable measurement of changes in the tie molecule length upon heating. We investigate the dependence of the percentage actuation observed upon heating, on the external applied force that stretches the tie molecules, the temperature range used for heating as well as the length and the number of tie molecules. Two molecular level mechanisms for actuation are identified. An entropically driven mechanism occurs at low applied forces and is applicable to all flexible polymers. A second mechanism due to conformational changes is observed for PVDF but not for PE at intermediate applied forces.