Adaptive and compliant wingtip devices enabled by additive manufacturing and multistable structures

Kimberly Gustafson, Luis Urrutia, Alexander Pankonien, Gregory Reich, Aimy Wissa

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


Multifunctional lifting surfaces can expand the mission capabilities of aerial vehicles with a minimal number of components added to the vehicle. This paper presents a bio-inspired segmented wingtip concept for lift enhancement enabled by passive structural tailoring and active bistable truss mechanisms. The development of wingtips stems from studies of birds with desirable flight capabilities. The structural characteristics and maneuverable changes of a bird's primary feathers during flight have identified three notable feather degrees of freedom: incidence angle, dihedral angle, and gap spacing. Wind tunnel experiments conducted on multi-wingtip systems have determined that different wingtip orientations and spacings are desired to enhance aerodynamic performance depending on the flight conditions. These results suggest that the wingtip degrees of freedom must be varied during flight to achieve optimal aerodynamic performance. This paper presents two structural concepts, one passive and one active, to achieve desired morphological wingtip parameters during flight. The passive structural concept exploits bend-twist coupling of additively manufactured composite laminate wingtips by using aerodynamic loads to induce passive shape adaptation of the composite wingtips to control the twist and dihedral angles. The active concept utilizes bistable truss mechanisms to vary the wingtip gap spacing. The force-displacement responses of bistable mechanisms and the bending and twist of bend-twist coupled composite wingtips are measured using a universal testing machine and Digital Image Correlation, respectively. Experimental results include the energy storage characterization of the bistable mechanisms as a function of material characteristics and the bend-twist coupling of the composite wingtips as a function of fabrication process and laminate properties.

Original languageEnglish (US)
Title of host publicationBioinspiration, Biomimetics, and Bioreplication IX
EditorsRaul J. Martin-Palma, Mato Knez, Akhlesh Lakhtakia
ISBN (Electronic)9781510625853
StatePublished - 2019
Externally publishedYes
EventBioinspiration, Biomimetics, and Bioreplication IX 2019 - Denver, United States
Duration: Mar 4 2019Mar 5 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceBioinspiration, Biomimetics, and Bioreplication IX 2019
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


  • Angle between the span of the base wing and the span of a wingtip
  • Chordwise distance between wingtips expressed as a percent of the base wing chord length
  • Wingtip angle of attack relative to the base wing angle of attack


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