Delft University of Technology 3D prints new smart material that breaks piezoelectric limits

TU Delft team 3D‑prints new smart material that breaks piezoelectric limits

By changing the structure of piezoelectrical materials and 3D-printing them, a research team at TU Delft, led by Saurav Sharma, has created a new type of smart material: piezoelectric truss metamaterials. These overcome the natural limitations of conventional piezoelectric materials, greatly improving their functionalities and applications. They can for example be used to create safer medical diagnostics and implants, better underwater sensors, more capable soft robots and noise cancelling sensors. The team published their findings in the Nature publication npj Metamaterials in December 2025.

Piezoelectric materials are used everywhere: in ultrasound machines, phone microphones, car airbags, and even energy‑harvesting gadgets. But standard piezoelectrical materials, like PZT or quartz, are limited by their crystal symmetry. For example: they usually can’t sense force in one direction without picking up noise from others.

Instead of trying to change the atomic crystals to increase the functionality of the materials, the team redesigned the structure of the material rather than its chemistry. By arranging the material in complex 3D truss lattices made from lead‑free, biocompatible ceramics, they created “metamaterials” that behave in ways natural crystals cannot.

Major findings:

• Breaking the symmetry barrier: the team discovered that by carefully shaping 3D‑printed truss structures, the material can show all of the possible ways a piezoelectric material can respond — not just the small handful allowed in nature.
• Superior energy harvesting: one of the designs produced over 48% more energy per unit weight than today’s most widely used piezoelectric material, PZT — even though it was made from a safer, lead‑free ceramic. This makes it far better at gathering energy or detecting pressure changes, such as those found underwater.
• Unidirectional sensing: the team achieved a rare effect where the material is much more sensitive to forces coming from the side than from straight on. Most materials behave the opposite way. This means it becomes possible to build sensors that pick up signals from one direction while ignoring unwanted noise from others.

Applications and impact: medical, marine and more  

The metamaterials created by the team pave the way for ‘animate’ materials that can sense and react to their environment. As the materials are lead-free and biocompatible they are inherently safer for the human body. They can be used e.g. for smart implants and ultrasound devices. Marine applications include underwater microphones and sensors with improved sensitivity. The materials can also be used for soft robots that move in more natural ways and for noise-filtering sensors that only pick up the signals needed. 

The impact of the work of Saurav Sharma, Sid Kumar, Jovana Jovanova and their team doesn’t stop there. It also contributes to the use and the manufacturing of more sustainable materials. Their findings show how these lead-free materials can actually outperform the traditional materials. They’ve also shown that in-gel 3D printing method is able to create highly complex piezoelectric trusses with great accuracy and shaping freedom.