Plantoid

The European CommissionEuropean Commission funded The Plantoid Project from 2012 to 2015. The goals of the project were 1) to abstract and synthesize with robotic artefacts the principles that enable plant roots to explore and adapt to underground environments and 2) formulate testable hypotheses and models.

The Plantoid Project was partly inspired by plant intelligence research findings from researchers such as Stefano Mancuso, Elisabeth Von Volkenburgh, Monica Gagliano and Frantisek Baluska. Baluska’s research into root behavior and responding to gravity and light demonstrated that plants make decisions based on sensory perceptions. Plants have also been found to communicate with other plants nearby by releasing volatiles as an alert to pathogen attacks. Mancuso was a partner in the Plantoid Project and the coordinator was Barbara Mazzolai at the Center for Micro-BioRobotics, Istituto Italiano di Tecnologia (IIT). Baluska’s research into root behavior and responding to gravity and light demonstrated that plants make decisions based on sensory perceptions. Plants have also been found to communicate with other plants nearby by releasing volatiles as an alert to pathogen attacks.

The concept of a plantoid was proposed by Mazzolai et al. (2010) to consist of task-specialized modules representing their natural counterparts and functionalities. The authors, lead by Stefano Mancuso, divide a plantoid can into three main sub-systems: 1) a main body with batteries, electronics and radio systems; 2) the root system, with electro-osmotic actuators; 3) the root apex with sensors. Furthermore, leaves are proposed to include photovoltaic cells.

The European Commission funded The Plantoid Project from 2012 to 2015. The goals of the project were 1) to abstract and synthesize with robotic artefacts the principles that enable plant roots to explore and adapt to underground environments and 2) formulate testable hypotheses and models.

The Plantoid Project was partly inspired by plant intelligence research findings from researchers such as Stefano Mancuso, Elisabeth Von Volkenburgh, Monica Gagliano and Frantisek Baluska. Mancuso was a partner in the Plantoid Project and the coordinator was Barbara Mazzolai at the Center for Micro-BioRobotics, Istituto Italiano di Tecnologia (IIT). Baluska’s research into root behavior and responding to gravity and light demonstrated that plants make decisions based on sensory perceptions. Plants have also been found to communicate with other plants nearby by releasing volatiles as an alert to pathogen attacks.

Stretching processes and mechanoperception of the plant root inspired the development of a soft robotics approach where capacitive sensitive elements conform to the shape of the soft body and follow its deformations. Plant cells possess mechanoperception in the ability of their cells to deform in response to external and internal mechanical forces. Plant roots respond to touch and bending with cell shape change and an internal signal of increased concentration of cytosolic calcium, Ca2+. The concept and design of a robotic soft body based on these plant root characteristics and built out of elastomers and conductive textiles was presented in Scientific ReportsScientific Reports in 2015 by a team led by Lucia Beccai at the Istituto Italiano di Tecnologia (ITT). The concave and convex sides of a bent body of distinguishable by their sensory responses. The sensing elements and the body act as one single entity rather than separate integrated parts.

It has been recognized that plant actuation and morphing mechanisms have applications in soft robotics. Plant cells and tissues provide movement capability and structural rigidity without the distinction between ‘actuators’ and ‘structures’ common to animal systems. Compared to animal muscular motions, plant movements are water driven, distributed, energy efficient and integrative. Inspiration from plants provides an opportunity to design movement with less part numbers. Plants can also provide inspiration for building soft robots out of compliant materials with the ability to interact in a soft and safe manner with the environment and humans.

Stretching processes and mechanoperception of the plant root inspired the development of a soft robotics approach where capacitive sensitive elements conform to the shape of the soft body and follow its deformations. Plant cells possess mechanoperception in the ability of their cells to deform in response to external and internal mechanical forces. Plant roots respond to touch and bending with cell shape change and an internal signal of increased concentration of cytosolic calcium, Ca2+. The concept and design of a robotic soft body based on these plant root characteristics and built out of elastomers and conductive textiles was presented in Scientific Reports in 2015 by a team led by Lucia Beccai at the Istituto Italiano di Tecnologia (ITT). The concave and convex sides of a bent body of distinguishable by their sensory responses. The sensing elements and the body act as one single entity rather than separate integrated parts.

It has been recognized that plant actuation and morphing mechanisms have applications in soft robotics. Plant cells and tissues provide movement capability and structural rigidity without the distinction between ‘actuators’ and ‘structures’ common to animal systems. Compared to animal muscular motions, plant movements are water driven, distributed, energy efficient and integrative. Inspiration from plants provides an opportunity to design movement with less part numbers.

A different approach to the development of climbing robots inspired by plant tendrils was presented by a group led by Camilla Pandolfi at the European Space Agency-Advanced Concepts Team in the Netherlands. In their 2015 paper they evaluated the movements and behaviors of the tendril, develop a robotic model and a kinematic simulator was used to visualize the system. Proof of concept prototypes were made of smart materials. Their design was based on climbing by searching for support, grasping-by-coiling and pulling behaviors. Using computer simulation, the searching phase was reproduced using a centralized motion so the tendrils span a cone in a 3D motion. If grasping-coiling sections of the device touch an obstacle, the circumnutation motion stops and the area that touched a surface reacts by bending in the direction of the stimulus. Shape Memory Alloys (SMAs) were chosen as material for their proof-of -concept prototypes, making use the ability of SMAs are able to recover a predetermined shape when heated.

A plantoid is a plant-inspired robot. Plantoids belong to the field of biorobotics where biological knowledge is used to develop innovative methodologies and technologies and bio-inspired robots serve as a tool to study living organisms. Characteristics and mechanisms of interacting with the environment such as the sensing and growing features of plant roots and the grasping behavior of tendrils have inspired plantoid designs. Potential applications proposed for plantoids include soil drilling, environmental monitoring, orthopedic supports and surgical robots.

A plantoid is a plant-inspired robot. Plantoids belong to the field of biorobotics where biological knowledge is used to develop innovative methodologies and technologies and bio-inspired robots serve as a tool to study living organisms. Characteristics such as the sensing and growing features of plant roots and the grasping behavior of tendrils have inspired plantoid designs. Potential applications proposed for plantoids include soil drilling, environmental monitoring, orthopedic supports and surgical robots.

The sensing principles of cucumber tendrils inspired the design of a sleeve for soft surgical manipulators, which could be developed into Robot-assisted Minimally Invasive Surgery (RMIS), where robotic manipulators pass through small incisions into the patient’s body. Cucumber tendrils have tactile papillae on their tendrils, which they use for climbing. A research team led by Kaspar Althoefer at the Centre for Advanced Robotic at Queen Mary University of London presented their design of soft manipulators with miniature sensing elements across the surface in the 2014 IEEE International Conference on Robotics and Automation (ICRA). The sensor network is reported to be capable of acquiring tactile information or haptic feedback for the surgeon. Each sensing element is a retractable hemispherical tactile that measures applied pressure. Optic fibers are used to transfer light signals modulated by the applied pressure from the sensing element to the proximal end of the robot arm. The device also takes inspiration from octopus morphology.

The authors suggest the incorporation of a sloughing mechanism such as that described in one of the group’s previous designs and a more optimized tip shape as potential improvements on their design. A mechanism is proposed where depositing the filament asymmetrically on the outer surface can allow bending capabilities. Potential applications for such a system include autonomous tunneling or space applications. As an approach to assembly, the growth process could be used for construction of structures. The root-like growing robot could also serve as a model to validate hypotheses on plant growth.

In 2017, Mazzolai’s team presented another root-like growing design that included a mechanism similar to cell sloughing and the ability to grow straight or to bend. . In plant roots cells grow outward from the tips and the sloughing of cells provide a low frictional interaction with the soil. These characteristics were incorporated into their plantoid prototype. Their system has an outward movement of a soft sleeve from the internal hole of a rigid tube to the external face. In addition the positive effect of root hairs in providing anchorage was imitated with lateral hairs which prevented upward movement. The body of the robot does not move with respect to the soil. The apical part performs the penetration using the growing mechanism which is a material deposition process achieved by the integration of a 3D printer inside the root. The robotic roots are able to grow straight or bend depending on the location of the deposition at the tip.

Each robot root includes a tubular body, a growing head and a tip with a sensor that commands the robot behaviors. Layer-by-layer deposition of the fused material in a tubular shape for the root body is achieved by simultaneous actions of feeding and rotational plotting. The 3D printer deposits polylactic acid (PLA) filament. By controlling the heater temperature and feeding speed the compliancy and softness of fused material can be modified. The plantoid with growing plant-like roots has potential applications in soil drilling, soil monitoring. Other suggested applications include passing oxygen, drugs or food in rescue scenarios and also in medical applications, such a device could be used for moving surgical tools.