Researchers at IIT Bhilai have developed a multifunctional smart hydrogel that can change its shape when heated and also help remove pollutants from wastewater, opening up possibilities in soft robotics, smart actuators and environmental cleanup. The research team, comprising Sudipta Paul, Priyank Sinha, Amul Jain and Dr. Sanjib Banerjee, developed the hydrogel using a specially designed four-arm star polymer along with acrylic acid, acrylamide and PEGDA. The material can be rapidly prepared using UVA light and formed into different structures, making it promising for developing future shape-changing devices.
A key feature of the hydrogel is its shape-memory behaviour. Researchers demonstrated this using a flower-like structure that opens when heated. The material achieved about 94% shape fixity and 85% shape recovery, returning to its programmed shape in around 25 seconds. It also retained its performance over repeated cycles. The hydrogel also showed impressive mechanical performance. In a demonstration, just 1 gram of dried hydrogel repeatedly lifted a 250-gram metal load, highlighting its potential for lightweight soft actuators and robotic systems.
The material was also tested for water purification, where it helped remove organic dyes such as methylene blue, rhodamine B and eosin B, along with toxic lead (Pb²⁺) ions from water. This combination of shape-changing ability, mechanical strength and pollutant removal makes the material particularly promising for multifunctional applications. The study has been published in the peer-reviewed journal Small Methods. The researchers believe that the developed platform could serve as a foundation for future smart and 4D-printable materials, combining programmable shape transformation with environmental remediation in a single hydrogel system. Linked to the research article
