skip to main content
DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mechanisms of local stress sensing in multifunctional polymer films using fluorescent tetrapod nanocrystals

Abstract

Nanoscale stress-sensing can be used across fields ranging from detection of incipient cracks in structural mechanics to monitoring forces in biological tissues. We demonstrate how tetrapod quantum dots (tQDs) embedded in block-copolymers act as sensors of tensile/compressive stress. Remarkably, tQDs can detect their own composite dispersion and mechanical properties, with a switch in optomechanical response when tQDs are in direct contact. Using experimental characterizations, atomistic simulations and finite-element analyses, we show that under tensile stress, densely-packed tQDs exhibit a photoluminescence peak shifted to higher energies (“blue-shift”) due to volumetric compressive stress in their core; loosely-packed tQDs exhibit a peak shifted to lower energies (“red-shift”) from tensile stress in the core. The stress-shifts result from the tQD's unique branched morphology in which the CdS arms act as antennas that amplify the stress in the CdSe core. Our nanocomposites exhibit excellent cyclability and scalability with no degraded properties of the host polymer. Colloidal tQDs allow sensing in many materials to potentially enable auto-responsive, smart structural nanocomposites that self-predict impending fracture.

Inventors:
; ; ; ; ; ; ;
Issue Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1576254
Patent Number(s):
10,429,256
Application Number:
15/607,158
Assignee:
The Regents of the University of California (Oakland, CA)
DOE Contract Number:  
AC02-05CH11231
Resource Type:
Patent
Resource Relation:
Patent File Date: 2017 May 26
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY

Citation Formats

Raja, Shilpa N., Zherebetskyy, Danylo, Wu, Siva, Ercius, Peter, Olson, Andrew C. K., Alvisatos, Paul, Ritchie, Robert O., and Govindjee, Sanjay. Mechanisms of local stress sensing in multifunctional polymer films using fluorescent tetrapod nanocrystals. United States: N. p., 2019. Web.
Raja, Shilpa N., Zherebetskyy, Danylo, Wu, Siva, Ercius, Peter, Olson, Andrew C. K., Alvisatos, Paul, Ritchie, Robert O., & Govindjee, Sanjay. Mechanisms of local stress sensing in multifunctional polymer films using fluorescent tetrapod nanocrystals. United States.
Raja, Shilpa N., Zherebetskyy, Danylo, Wu, Siva, Ercius, Peter, Olson, Andrew C. K., Alvisatos, Paul, Ritchie, Robert O., and Govindjee, Sanjay. Tue . "Mechanisms of local stress sensing in multifunctional polymer films using fluorescent tetrapod nanocrystals". United States. https://www.osti.gov/servlets/purl/1576254.
@article{osti_1576254,
title = {Mechanisms of local stress sensing in multifunctional polymer films using fluorescent tetrapod nanocrystals},
author = {Raja, Shilpa N. and Zherebetskyy, Danylo and Wu, Siva and Ercius, Peter and Olson, Andrew C. K. and Alvisatos, Paul and Ritchie, Robert O. and Govindjee, Sanjay},
abstractNote = {Nanoscale stress-sensing can be used across fields ranging from detection of incipient cracks in structural mechanics to monitoring forces in biological tissues. We demonstrate how tetrapod quantum dots (tQDs) embedded in block-copolymers act as sensors of tensile/compressive stress. Remarkably, tQDs can detect their own composite dispersion and mechanical properties, with a switch in optomechanical response when tQDs are in direct contact. Using experimental characterizations, atomistic simulations and finite-element analyses, we show that under tensile stress, densely-packed tQDs exhibit a photoluminescence peak shifted to higher energies (“blue-shift”) due to volumetric compressive stress in their core; loosely-packed tQDs exhibit a peak shifted to lower energies (“red-shift”) from tensile stress in the core. The stress-shifts result from the tQD's unique branched morphology in which the CdS arms act as antennas that amplify the stress in the CdSe core. Our nanocomposites exhibit excellent cyclability and scalability with no degraded properties of the host polymer. Colloidal tQDs allow sensing in many materials to potentially enable auto-responsive, smart structural nanocomposites that self-predict impending fracture.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {10}
}

Patent:

Save / Share: