Smart Materials are materials with one or more properties that can be significantly changed in a controlled fashion by externally applied stimuli such as stress, temperature, and electric/magnetic fields. The response can be reversible and demonstrated by changes in physical properties such as shape, stiffness, and viscosity in a specific manner. Smart materials do not constitute just a discrete part of the system, but can also be the system itself, representing sensing, actuation, and mechanical functions. Properties such as self-adaptability, self-sensing, self-healing, and memory enable their usage in numerous applications, including biomedical devices, consumer electronics, lightweight construction, aerospace, and defense. Design of smart materials is technically advanced and requires interdisciplinary knowledge. Existing methods are often limited to specific materials and a certain manufacturing/processing method. Therefore, newer techniques are needed to design such materials from different sources with flexible manufacturing methods.


Technology Overview

Researchers at Northeastern designed a new hybrid structured material composed of hard cells or inclusions connected via specially designed soft components, such as soft networks, soft hinges, or bilayer joints. The soft components are responsive to external stimuli, such as mechanical load, temperature, humidity, and electric/magnetic fields. Due to the special design and responsive properties of the soft components, this family of structured materials can show tunable expansion coefficients in a very wide range from negative to positive ones. The design is achieved by different materials and various manufacturing/processing approaches, such as coating, adhesion, mechanical jointing, and 3D printing. The new mechanical metamaterials can have applications in designing new sensors, actuators, biomedical devices, smart digital displays, smart clothes, and wearable devices. This technology can be prepared at the minimum cost due to the versatility of manufacturing processes and materials.



  • Controllable expansion coefficient
  • Wide range of coefficient from negative to positive
  • Use for different expansion coefficients, including temperature, humidity, electric-magnetic field
  • Applicable to different materials and functions
  • Easy and versatile manufacturing/processing methods
  • Cost-effective



  • Design of sensors, actuator, and fasteners
  • Design of responsive filters or valves to control fluid/particle flow
  • Biomedical materials and stents
  • Drug delivery
  • Smart digital displays
  • Smart clothes and wearable device
  • Camouflage



  • Research collaboration
  • Licensing
  • Commercial partner
Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
Yaning Li
3D printing
4D Printing
Expansion coefficient
Mechanical Metamaterials