Session: VIB-13-01: Dynamics of Biological, Bio-Inspired and Biomimetic Systems

Paper Number: 118055

118055 - Experimental Evaluation of Wing Hinge Mechanics in Bumblebees 

Insects are remarkably efficient fliers despite flapping flight being the most energetically expensive form of locomotion per unit time. It is believed that insects store potential energy in ``series'' and ``parallel'' elastic elements within their exoskeletal structure to help reduce some of this energetic cost. The ``parallel'' element represents the stiffness of the indirect flight muscles and the flexible exoskeleton surrounding them. The series element represents the torsional stiffness of the soft matter within the wing hinge, a complex lever mechanism which amplifies thorax deformation into larger wing rotation. The influence of each element on system energetics is not well known, especially the series element. The parallel stiffness has been measured experimentally by directly compressing the thorax in insect cadavers and measuring reaction forces to determine an approximate spring constant. The series stiffness is challenging to measure directly because insect wings often disengage from the drive train post-mortem, thus preventing the ability to measure angular displacement and resulting moment.  In this study we question if the series element behaves as a static or dynamic transmission between the thorax and wings (i.e., the relative phase between thorax deformation and wing rotation is zero or some nonzero value respectively). To answer this question, we experimentally evaluated changes in flight mechanics of bumblebees subject to wing damage by simultaneously measuring thorax deformation and wing rotation. We found that the phase difference between the thorax and wings did change with wing treatment, where the wing rotation led thorax deformation by 15-20 degrees in phase.

Presenting Author: Braden Cote Montana State University

Presenting Author Biography: Braden graduated from Gonzaga University in 2020 with a BS in Mechanical Engineering. He is working on his PhD in Mechanical Engineering. His research focuses on the system level modeling of flying insects. He is developing comprehensive dynamic models to describe the behavior of the flight mechanism as a whole, synthesizing previously compartmentalized work that studied the various components of the flight mechanism (i.e. thorax, wing, and wing hinge). After graduating Braden hopes to enter to the robotics or aerospace industry in an R&D role or possibly start his own aerial robotics company.

Authors:

Braden Cote Montana State University
Mark Jankauski Montana State University