From the labs. Nano road safety sensor

A prototype of a road safety sensor that can be implanted at high-risk and accident-prone curves has been developed from a new polymer nanocomposite with pressure sensing and energy harvesting properties. 

Researchers from the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have developed the polymer nanocomposite and used it to develop a prototype of a road safety sensor. 

The prototype may be implanted in a movable ramp and secured to the road just 100 metres before the high-risk turning points. 

Thus, any vehicle approaching from the opposite side will see the signal on a screen and be alerted. This prototype works on the principle of piezoelectric effect, so it can generate energy that can be stored and used to power electronic gadgets as well. 

The novel polymer nanocomposite used in the prototype has been made out of transition metal dichalcogenide. 

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The scientists — Ankur Verma, Dr Arjun Hari Madhu, and Dr Subash Cherumannil Karumuthil — synthesised vanadium disulphide with a high surface charge, which has the ability to enhance the piezoelectric characteristics of polymers. 

Polymer nanocomposite films were prepared by integrating nanoparticles in various concentrations into a well-known piezoelectric polymer, poly (vinylidene difluoride). 

Further, they investigated how the surface charge of nanoparticles will affect the piezoelectric properties of the polymer nanocomposite. 

In addition, a laboratory-scale demonstration of a road safety sensor and smart door was established, with the prototype as a pressure sensor.

New material for nanodevices

A breakthrough in understanding the process of controlling the assembly of tiny molecular units into complex structures holds promise for creating new materials that could revolutionise industries like electronics, healthcare, and beyond. 

Supramolecular self-assembly is a process where small molecules spontaneously organise into larger, well-defined structures without external direction. Understanding this process is crucial for creating new organic materials that can be used to develop nanodevices — tiny machines useful in performing specific tasks at the molecular level, such as drug delivery to specific parts of the body. 

A group of researchers at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, in collaboration with researchers from the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, explored the self-assembly behaviour of specific molecules called ‘chiral amphiphilic naphthalene diimide derivatives’. They experimented with two different methods of assembling these molecules — solution phase assembly and air-water interface assembly. 

The former involved the assembling of molecules in a liquid solution, leading to the formation of spherical nanoparticles. These tiny particles displayed unique optical properties, such as strong mirror-imaged circular dichroism signals, which are important for materials that interact with light in precise ways. 

The air-water interface assembly involved assembling molecules at the boundary between air and water, which the researchers also tested. At the air-water interface, instead of forming spherical nanoparticles, the molecules arranged themselves into flat, two-dimensional layers with irregular edges. Interestingly, these layers did not exhibit the same optical properties as the solution-assembled nanoparticles, indicating that the environment in which molecules assemble plays a critical role in determining their final structure and properties.