3D-printed ready-to-use variable-stiffness structures

Majid Taghavi, Tim Helps, Boxiong Huang, Jonathan Rossiter

Research output: Contribution to journalArticle (Academic Journal)peer-review

28 Citations (Scopus)
566 Downloads (Pure)


Various physical phenomena have been used to develop variable-stiffness (VS) materials and structures, but all have involved some element of manual fabrication, which limits their applications. In contrast, here we show fully 3D-printed monolithic VS structures that can be used direct from the printer. Thermally responsive polylactic acid (PLA) and conductive Graphene PLA (GPLA), are combined in-printer to deliver a new framework for temperature-controlled 3D VS structures. The embedded GPLA acts as a heating element, and both it and the surrounding PLA can be transitioned from rigid to soft using simple Joule heating because of the glass transition behavior of PLA. The mechanical and electrical properties of printed composite VS structures are studied. The great potential of this technology is demonstrated in a prototype variable-stiffness orthotic for Foot Drop.
Original languageEnglish
Pages (from-to)2402-2407
Number of pages6
JournalIEEE Robotics and Automation Letters
Issue number3
Early online date7 Mar 2018
Publication statusPublished - Jul 2018


Dive into the research topics of '3D-printed ready-to-use variable-stiffness structures'. Together they form a unique fingerprint.

Cite this