Kinetic Shades: Designing a Shape-Morphing Device with Bistable Laminates and Shape Memory Actuators

In recent years, there has been a renewed interest in kinetic systems made with smart materials that can adapt to changing environmental conditions. This paper describes design research to develop and improve the design of a holder unit that is the basic component of a kinetic bistable shading system. The holder comprises four bistable flaps and linear actuators with shape memory alloy (SMA) springs. The linear actuators force the bistable flaps to snap into their opened and closed positions. Two experimental studies were conducted: (1) a study to find an adequate SMA and biasing springs combination for a linear actuator; and (2) a shape optimization study. The first study aimed to find an adequate configuration for the linear actuator, which has both SMA and biasing springs. In the study, data obtained by image analysis were analyzed statistically to understand which combination of SMA and biasing springs resulted in the largest displacement. The second study used topology optimization to obtain a 25% reduction in the total volume of the holder unit compared to the initial design, resulting in a lighter kinetic structure. The paper describes the two studies conducted, highlighting the resulting improvements in the holder unit for the kinetic screen.