A piezoelectric-based advanced wearable: Obstacle avoidance for the visually impaired built into a backpack

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


Visual impairment constitutes a compelling issue for our society. The aging of our population will cause a rise in the number of individuals affected by these debilitating conditions, which often challenge people in their daily routine and bear significant healthcare costs and consequences on society at large. Technological progress offers unique means to improve life conditions for the visually impaired, who still rely on low-tech systems, such as canes and service dogs. Here, we present a novel design for a piezoelectric belt integrated into a backpack, which can provide vibrotactile stimulation to the abdomen to signal the presence of obstacles. The belt is composed of an array of ten macro-fiber composite (MFC) actuators, arranged in a matrix of five columns by two rows. Obstacle identification and localization is afforded by a computer vision system, developed by our collaborators. The output from the array of actuators is controlled by the computer vision system, such that, if an obstacle is identified in a certain "capture field", the corresponding actuator in an egocentric and spatiotopically preserved fashion is activated. The actuators comprise an encapsulated aluminum-backed MFC, driven by a tunable astable multivibrator. The resonance frequency of the actuators is tailored by adding a variable mass to a hollow cylinder fashioned as a protusion secured to the tactor, transmitting vibrations from the MFC to the skin of the human-in-the-loop. This new design allows us to enhance the peak-to-peak displacement of actuators of more than a tenfold factor over the 10-200 Hz frequency range, thereby surpassing, with a robust margin, the 50 μm threshold necessary for reliable discrimination given abdominal somatosensation.

Original languageEnglish (US)
Title of host publicationNano-, Bio-, Info-Tech Sensors, and 3D Systems IV
EditorsJaehwan Kim
ISBN (Electronic)9781510635333
StatePublished - 2020
EventNano-, Bio-, Info-Tech Sensors, and 3D Systems IV 2020 - None, United States
Duration: Apr 27 2020May 8 2020

Publication series

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


ConferenceNano-, Bio-, Info-Tech Sensors, and 3D Systems IV 2020
Country/TerritoryUnited States


  • Abdomen stimulation
  • Haptic device
  • Macrofiber composites
  • Reduced-order modeling
  • Resonance

ASJC Scopus subject areas

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


Dive into the research topics of 'A piezoelectric-based advanced wearable: Obstacle avoidance for the visually impaired built into a backpack'. Together they form a unique fingerprint.

Cite this