Non-Conventional Deformations: Materials and Actuation

Abstract

This paper reviews materials and structures displaying non-conventional deformations as a response to different actuations (e.g., electricity, heat and mechanical loading). Due to the various kinds of actuation and targeted irregular deformation modes, the approaches in the literature show great diversity. Methods are systematized and tabulated based on the nature of actuation. Electrically and mechanically actuated shape changing concepts are discussed individually for their significance, while systems actuated by heat, pressure, light and chemicals are condensed in a shared section presenting examples and main research trends. Besides scientific research results, this paper features examples of real-world applicability of shape changing materials, highlighting their industrial value.

Keywords: composites; coupling; morphing; shape adaptation.

Figure 1

Electro-bonded laminate working principle [31].

Figure 2

Bi- and trilayer polyaniline coated electroactive paper actuators [32].

Figure 3

Schematic working principle of shape memory polymers [52].

Figure 4

Thermally actuated origami folding: (a) cooling, deswelling and flattening, (b) heating, swelling and folding [58].

Figure 5

Schematics of a pneumatic buckling actuator. (a) actuator structure, (b) actuator operation, (c) pneumatic actuation [73].

Figure 6

Bistable laminate (a) reference flat plate, (b) and (c) stable geometries [89].

Figure 7

Undeformed and deformed geometry of a marine turbine with bend-twist coupled composite blades for improved efficiency [8].

Figure 8

Passively morphing aircraft capable of shape adaptation to different flight conditions [106].

Figure 9

Schematic abstract of approaches to achieve non-conventional shape changes with.