Researchers in Italy have created a new 4D-printed, biodegradable, soft robot shaped like a seed that can move through soil, changing shape in response to changes in humidity. This device has great potential as a new way of monitoring the environment.
4D printing is the process of using 3D printing to create objects that can change shape and properties depending on environmental factors such as light and temperature. This technique was previously used to create self-assembling programmable material technology.
We are currently using 4D technology to create a soft robot that can analyze soil. Inspired by the seed structure of the South African geranium (pelargonium appendix), researchers at the Istituto Italiano di Tecnologia in Genoa have created the first biomimetic, biodegradable seed robot.
“Our research began with observations of nature, with the aim of mimicking the strategies of organisms and their structures, and replicating them with robotic technologies that have less environmental impact in terms of energy and pollution.” said Barbara Mazzolai, the study’s corresponding author. .
The seeds of the rhododendron family of flowering plants, including geraniums, exploit their hygroscopic (humidity-activated) properties by detaching themselves under appropriate environmental conditions. After detaching, they change shape and penetrate the soil independently, increasing the chances of germination.
After thoroughly investigating the structure and biomechanics of natural seeds, researchers combined 3D printing and electrospinning techniques to replicate them. Electrospinning is a fiber manufacturing method that uses electrical forces to draw charged polymers down to fiber diameters on the order of hundreds of nanometers.
The research team used fused deposition modeling (FDM) to print a substrate layer composed of polycaprolactone (PCL), a biodegradable thermoplastic polyester. PCL was activated using oxygen plasma to make it more water attracting (hydrophilic). They then added electrospun hygroscopic fibers composed of a polyethylene oxide shell and a cellulose nanocrystal core to the substrate.
In tests, the soft robot explored a soil sample and adapted its shape to interact with its roughness and cracks. It was very energy efficient and could lift about 100 times its weight.
The video below, made by Istituto Italiano di Tecnologia, shows how the robot seeds reacted to the soil during testing.
First biodegradable seed robot that changes shape in response to humidity
The new device offers a new way to discreetly monitor the planet, researchers say.
“With this latest research, we have further proven that we can create innovative solutions that not only have the purpose of monitoring the well-being of our planet, but do so without altering it.
Researchers hope that the device’s low cost, simple design, and data collection capabilities will be particularly useful in remote locations.
“These biodegradable and energy-autonomous robots will be used as wireless, battery-free tools for surface soil exploration and monitoring,” said Luca Cecchini, lead author of the study. increase. “This bio-inspired approach has allowed us to create a low-cost instrument that can be used to collect field data with high spatial and temporal resolution, especially in remote areas where surveillance data is not available. “
The study was published in a journal advanced science.
Source: Italian Institute of Technology
