Orchestrated Movement Sequences and Shape-Memory-like Effects in Pine Cones.

Hygroscopic seed-scale movement is responsible for the weather-adaptive opening and closing of pine cones and for facilitating seed dispersal under favorable environmental conditions. Although this phenomenon has long been investigated, many involved processes are still not fully understood. To gain a deeper mechanical and structural understanding of the cone and its functional units, namely the individual seed scales, we have investigated their desiccation- and wetting-induced movement processes in a series of analyses and manipulative experiments.

Digital image correlation techniques for motion analysis and biomechanical characterization of plants.

Temporally and spatially complex 3D deformation processes appear in plants in a variety of ways and are difficult to quantify in detail by classical cinematographic methods. Furthermore, many biomechanical test methods, e.g.

Cross-Sectional 4D-Printing: Upscaling Self-Shaping Structures with Differentiated Material Properties Inspired by the Large-Flowered Butterwort ().

Extrusion-based 4D-printing, which is an emerging field within additive manufacturing, has enabled the technical transfer of bioinspired self-shaping mechanisms by emulating the functional morphology of motile plant structures (e.g., leaves, petals, capsules).

Chemical Gradients in Polymer-Modified Paper Sheets-Towards Single-Layer Biomimetic Soft Robots.

Biomimetic actuators are typically constructed as functional bi- or multilayers, where actuating and resistance layers together dictate bending responses upon triggering by environmental stimuli. Inspired by motile plant structures, like the stems of the false rose of Jericho (), we introduce polymer-modified paper sheets that can act as soft robotic single-layer actuators capable of hygro-responsive bending reactions. A tailored gradient modification of the paper sheet along its thickness entails increased dry and wet tensile strength and allows at the same time for hygro-responsiveness.

The cracking of Scots pine () cones.

Pine cones show functionally highly resilient, hygroscopically actuated opening and closing movements, which are repeatable and function even in millions of years old, coalified cones. Although the functional morphology and biomechanics behind the individual seed scale motions are well understood, the initial opening of the cone, which is often accompanied by an audible cracking noise, is not. We therefore investigated the initial opening events of mature fresh cones of Scots pine () and their subsequent motion patterns.

Chemonastic Stalked Glands in the Carnivorous Rainbow Plant LINDL. (Byblidaceae, Lamiales).

Carnivorous rainbow plants (, Byblidaceae, Lamiales) possess sticky flypaper traps for the capture, retention, and digestion of prey (mainly small insects). The trapping system is based on a multitude of millimeter-sized glandular trichomes (also termed stalked glands), which produce adhesive glue drops. For over a century, the trapping system of was considered passive, meaning that no plant movement is involved.

Shapeshifting in the Venus flytrap (): Morphological and biomechanical adaptations and the potential costs of a failed hunting cycle.

The evolutionary roots of carnivory in the Venus flytrap () stem from a defense response to plant injury caused by, e.g., herbivores.

Facing the Green Threat: A Water Flea's Defenses against a Carnivorous Plant.

Every ecosystem shows multiple levels of species interactions, which are often difficult to isolate and to classify regarding their specific nature. For most of the observed interactions, it comes down to either competition or consumption. The modes of consumption are various and defined by the nature of the consumed organism, e.

Smooth or with a Snap! Biomechanics of Trap Reopening in the Venus Flytrap (Dionaea muscipula).

Fast snapping in the carnivorous Venus flytrap (Dionaea muscipula) involves trap lobe bending and abrupt curvature inversion (snap-buckling), but how do these traps reopen? Here, the trap reopening mechanics in two different D. muscipula clones, producing normal-sized (N traps, max. ≈3 cm in length) and large traps (L traps, max.

The Structural and Mechanical Basis for Passive-Hydraulic Pine Cone Actuation.

The opening and closing of pine cones is based on the hygroscopic behavior of the individual seed scales around the cone axis, which bend passively in response to changes in environmental humidity. Although prior studies suggest a bilayer architecture consisting of lower actuating (swellable) sclereid and upper restrictive (non- or lesser swellable) sclerenchymatous fiber tissue layers to be the structural basis of this behavior, the exact mechanism of how humidity changes are translated into global movement are still unclear. Here, the mechanical and hydraulic properties of each structural component of the scale are investigated to get a holistic picture of their functional interplay.

The effects of substrate porosity, mechanical substrate properties and loading conditions on the attachment performance of the Mediterranean medicinal leech ().

The ectoparasitic lifestyle of the Mediterranean medicinal leech () requires reliable functioning of its attachment organs (i.e. anterior and posterior suction discs) on multiple habitat- and host-specific surfaces under both normal and shear stresses.

Structural gradients and anisotropic hydraulic conductivity in the enigmatic eel traps of carnivorous corkscrew plants (Genlisea spp.).

Premise: Among the sophisticated trap types in carnivorous plants, the underground eel traps of corkskrew plants (Genlisea spp., Lentibulariaceae) are probably the least understood in terms of their functional principle. Here, we provide a detailed analysis of structural and hydraulic features of G.

Bio-Inspired Motion Mechanisms: Computational Design and Material Programming of Self-Adjusting 4D-Printed Wearable Systems.

This paper presents a material programming approach for designing 4D-printed self-shaping material systems based on biological role models. Plants have inspired numerous adaptive systems that move without using any operating energy; however, these systems are typically designed and fabricated in the form of simplified bilayers. This work introduces computational design methods for 4D-printing bio-inspired behaviors with compounded mechanisms.

Self-Actuated Paper and Wood Models: Low-Cost Handcrafted Biomimetic Compliant Systems for Research and Teaching.

The abstraction and implementation of plant movement principles into biomimetic compliant systems are of increasing interest for technical applications, e.g., in architecture, medicine, and soft robotics.

Programming sequential motion steps in 4D-printed hygromorphs by architected mesostructure and differential hygro-responsiveness.

Through their anisotropic cellular mesostructure and differential swelling and shrinking properties, hygroscopic plant structures move in response to changes in the environment without consuming metabolic energy. When the movement is choreographed in sequential time steps, either in individual structures or with a coordinated interplay of various structural elements, complex functionalities such as dispersal and protection of seeds are achieved. Inspired by the multi-phase motion in plant structures, this paper presents a method to physically program the timescale and the sequences of shape-change in 4D-printed hygromorphic structures.

Complexity and diversity of motion amplification and control strategies in motile carnivorous plant traps.

Similar to animals, plants have evolved mechanisms for elastic energy storage and release to power and control rapid motion, yet both groups have been largely studied in isolation. This is exacerbated by the lack of consistent terminology and conceptual frameworks describing elastically powered motion in both groups. Iconic examples of fast movements can be found in carnivorous plants, which have become important models to study biomechanics, developmental processes, evolution and ecology.

Snapshot prey spectrum analysis of the phylogenetically early-diverging carnivorous Utricularia multifida from U. section Polypompholyx (Lentibulariaceae).

Utricularia multifida is carnivorous bladderwort from Western Australia and belongs to a phylogenetically early-diverging lineage of the genus. We present a prey spectrum analysis resulting from a snapshot sampling of 17 traps-the first of this species to our knowledge. The most abundant prey groups were Ostracoda, Copepoda, and Cladocera.

Form, Structure, and Function: How Plants vs. Animals Solve Physical Problems.

Plants and animals have evolved solutions for a wide range of mechanical problems, such as adhesion and dispersal. Several of these solutions have been sources for bio-inspiration, like the Lotus Effect for self-cleaning surfaces or Velcro for adhesion. This symposium brought together plant and animal biomechanics researchers who tackle similar problems in different systems under the unifying theme of structure-function relations with relevance to bio-inspiration.

Functional-morphological analyses of the delicate snap-traps of the aquatic carnivorous waterwheel plant (Aldrovanda vesiculosa) with 2D and 3D imaging techniques.

Background And Aims: The endangered aquatic carnivorous waterwheel plant (Aldrovanda vesiculosa) catches prey with 3-5-mm-long underwater snap-traps. Trapping lasts 10-20 ms, which is 10-fold faster than in its famous sister, the terrestrial Venus flytrap (Dionaea muscipula). After successful capture, the trap narrows further and forms a 'stomach' for the digestion of prey, the so-called 'sickle-shaped cavity'.

Exploring the attachment of the Mediterranean medicinal leech () to porous substrates.

Haematophagous ectoparasites must ensure a reliable hold to their host during blood meals and, therefore, have evolved a broad spectrum of versatile and effective attachment mechanisms. The Mediterranean medicinal leech (), for example, uses suction on both smooth and textured air-tight substrates. However, preliminary studies showed that is also capable of attaching itself to air-permeable substrates, where suction does not work.

Snapping mechanics of the Venus flytrap ().

The mechanical principles for fast snapping in the iconic Venus flytrap are not yet fully understood. In this study, we obtained time-resolved strain distributions via three-dimensional digital image correlation (DIC) for the outer and inner trap-lobe surfaces throughout the closing motion. In combination with finite element models, the various possible contributions of the trap tissue layers were investigated with respect to the trap's movement behavior and the amount of strain required for snapping.

Plant Movements as Concept Generators for the Development of Biomimetic Compliant Mechanisms.

Plant movements are of increasing interest for biomimetic approaches where hinge-free compliant mechanisms (flexible structures) for applications, for example, in architecture, soft robotics, and medicine are developed. In this article, we first concisely summarize the knowledge on plant movement principles and show how the different modes of actuation, that is, the driving forces of motion, can be used in biomimetic approaches for the development of motile technical systems. We then emphasize on current developments and breakthroughs in the field, that is, the technical implementation of plant movement principles through additive manufacturing, the development of structures capable of tracking movements (tropisms), and the development of structures that can perform multiple movement steps.

Mechanical Ecology-Taking Biomechanics to the Field.

Synopsis Interdisciplinary research can have strong and surprising synergistic effects, leading to rapid knowledge gains. Equally important, it can help to reintegrate fragmented fields across increasingly isolated specialist sub-disciplines. However, the lack of a common identifier for research "in between fields" can make it difficult to find relevant research outputs and network effectively.