A team of scientists led by Nanyang Technological University in Singapore (NTU Singapore) has developed a device that can deliver electrical signals to and from plants, opening the door to new technologies that make use of plants.
The NTU team developed their plant ‘communication’ device by attaching a conformable electrode (a piece of conductive material) on the surface of a Venus flytrap plant using a soft and sticky adhesive known as hydrogel. With the electrode attached to the surface of the flytrap, researchers can achieve two things: pick up electrical signals to monitor how the plant responds to its environment, and transmit electrical signals to the plant, to cause it to close its leaves.
Scientists have known for decades that plants emit electrical signals to sense and respond to their environment. The NTU research team believe that developing the ability to measure the electrical signals of plants could create opportunities for a range of useful applications, such as plant-based robots that can help to pick up fragile objects, or to help enhance food security by detecting diseases in crops early.
However, plants’ electrical signals are very weak, and can only be detected when the electrode makes good contact with plant surfaces. The hairy, waxy, and irregular surfaces of plants make it difficult for any thin-film electronic device to attach and achieve reliable signal transmission.
To overcome this challenge, the NTU team drew inspiration from the electrocardiogram (ECG), which is used to detect heart abnormalities by measuring the electrical activity generated by the organ.
Seeking to improve the performance of their plant ‘communication’ device, the NTU scientists also collaborated with researchers at the Institute of Materials Research and Engineering (IMRE), a unit of Singapore’s Agency for Science, Technology and Research (A*STAR).
Results from this separate study, published in the scientific journal Advanced Materials in March, found that by using a type of hydrogel called thermogel – which gradually transforms from liquid to a stretchable gel at room temperature – it is possible to attach their plant ‘communication’ device to a greater variety of plants (with various surface textures) and achieve higher quality signal detection, despite plants moving and growing in response to the environment.
Moving forward, the NTU team is looking to devise other applications using the improved version of their plant ‘communication’ device.
The video below can also be watched on YouTube here.
Source: Nanyang Technological University, Singapore. Read the full press release here.
Related papers: “An on-demand plant-based actuator created using conformable electrodes“, published online in Nature Electronics, 25 January 2021.
“A Morphable Ionic Electrode Based on Thermogel for Non-invasive Hairy Plant Electrophysiology“, published online in Advanced Materials, 4 March 2021.
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