Digital Theses Archive


Tesi etd-03252021-170655

Type of thesis
E-mail address
Multifunctional miniature machines inspired by climbing plants
Scientific disciplinary sector
Istituto di Biorobotica - BIOROBOTICS
relatore Prof.ssa LASCHI, CECILIA
  • biodegradable materials
  • Bioinspiration
  • climbing plants
  • ecosystem conservation
  • microfabrication
  • smart attachment devices
  • soft materials
  • soft robotics
  • two photon lithography
  • unstructured environments
Exam session start date
One of the major challenges in robotics and engineering is to develop efficient technological solutions that can cope with complex environments and unpredictable constraints. Taking inspiration from natural organisms is a well-known approach to tackling these issues. Climbing plants are an important, yet innovative, source of inspiration due to their ability to adapt to diverse habitats, and can be used as a model for prototyping soft robots and smart devices for exploration and monitoring in unstructured and dynamic environments.<br>This PhD dissertation relates to the development of novel soft- and miniature machines inspired by climbing plants. With this in mind, the morphological and biomechanical features of selected natural plant species were investigated to extract the biological benchmarks necessary for an artificial translation. The extracted benchmarks were used to design climbing plant-inspired systems, made with different manufacturing techniques, including two-photon lithography, moulding and casting of different materials.<br>Inspired by the ratchet-like attachment mechanism of the hook-climber Galium aparine, flexible micro-patterned devices were developed and fully characterized for reversible attachment via mechanical interlocking over a wide range of rough surfaces. The devices have shown the strongest shear-dependent attachment to skin tissues and textiles, showing high potential for clothing, biomedical and soft- and micro-robotics fields. Then, flexible and self-dissolving G. aparine-inspired devices were proposed for multifunctional directional attachment to natural plant leaves surfaces, allowing precision plant monitoring, locomotion and molecular delivery. These devices may lead to a novel vision by acting in the dense vegetation for mapping and preserving the ecosystem. Three different hook-based environmental demonstrators were built for precision leaf applications, including miniature soft sensors measuring temperature, humidity and light in leaf proximity, on-leaf-locomoting light-driven robots, and self-dissolving hooks for in-plant drug delivery. In addition, a micro-snap fastener with micro-spines was developed taking inspiration from the shape of Rosa arvensis prickles. These devices demonstrate to be promising for controllable release of objects, showing high potential in robotic and space applications for manipulation and sampling at microscale level. Preliminary results about the variation of biomechanical parameters along hook-climber stems and a deeper 3D reconstruction of twining plants and tendrils are reported.<br>This research pushes forward the perspective to use multifunctional climbing plant-inspired machines in natural unstructured environments, facing the complexity to operate in a dynamic real-world scenario.