45
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_8
Chapter 8
Dynamic Rugae Strain Localizations and Instabilities in Soft
Viscoelastic Materials During Inertial Microcavitation
Jin Yang, Harry C. Cramer III, and Christian Franck
Abstract To constitutively characterize soft material large deformation properties at high loading rates (10
3
–10
8
s
−1
), we
recently developed an experimental technique called Inertial Microcavitation Rheometry (IMR). Here, inertial cavitation
bubbles are generated through a spatially focused pulsed laser, e.g., hydrogels, tissues, and various polymeric specimens. By
recording the spatiotemporally resolved bubble dynamics via high-speed videography, a combined experimental and theoretical investigation of single bubble cavitation in soft viscoelastic materials has been conducted, where we observe evidence
of strain localization and surface instabilities near the bubble wall during bubble expansion and collapse. We provide direct
experimental observation of how strain localization can lead to various types of surface instabilities within a gel- like soft
material giving rise to kink, wrinkle, and crease patterns. These types of dynamic rugae patterns and associated strain concentrations might be of significant interest in medical and engineering applications that utilize or encounter microcavitation,
e.g., during ultrasound or laser surgeries, or traumatic brain injuries.
Keywords Inertial cavitation · Hydrogel · High strain-rate · Rugae instability · Crease
8.1 Introduction
Cavitation is a common phenomenon in many biological systems and medical applications [1, 2]. For example, inertial cavitation can cause serious damage to soft tissues and cells [3–5]. On the other side, when harnessed carefully, bubble cavitation
can be used beneficially in many surgical and medical procedures, for example, in cataract laser surgery, lithotripsy, and
histotripsy applications [6, 7]. In addition, well-controlled laser or ultrasound-induced cavitation provides an effective
method for characterizing soft material viscoelastic properties at extremely high strain-rates on the order of O(10
3
)–O(10
8
)
s
−1
. Recently, we developed an experimental technique called Inertial Microcavitation Rheometry (IMR) [8–10]. Here, inertial cavitation bubbles are generated through a spatially focused pulsed laser inside a soft material of interest. By recording
the spatiotemporally resolved bubble dynamics via high-speed videography, a combined experimental and theoretical investigation of single bubble cavitation in soft viscoelastic materials has been conducted. During bubble expansion-collapse
cycles, we observe evidence of strain localization and surface instabilities near the bubble wall. These types of dynamic
rugae patterns and associated strain concentrations might be of significant interest in many medical and engineering applications that utilize or encounter microcavitation, e.g., ultrasound or laser surgeries, or traumatic brain injuries. In this extended
abstract, we will present some experimental results providing direct evidence of the existence of dynamic surface instabilities
during inertial cavitation.
In this chapter, first, we introduce our material preparation and experimental setup in Sects. 8.2 and 8.3. Then we show
and analyze our experimental results in Sect. 8.4. Finally, we present some conclusions in Sect. 8.5.
J. Yang (*) · C. Franck
Department of Mechanical Engineering, University of Wisconsin- Madison, Madison, WI, USA
e-mail: jyang526@wisc.edu; cfranck@wisc.edu
H. C. Cramer III
School of Engineering, Brown University, Providence, RI, USA
Center for Biomedical Engineering, Brown University, Providence, RI, USA
e-mail: harry_cramer@brown.edu
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
L. Lamberson et al. (eds.), Dynamic Behavior of Materials, Volume 1, Conference Proceedings of the Society
for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59947-8_8
Chapter 8
Dynamic Rugae Strain Localizations and Instabilities in Soft
Viscoelastic Materials During Inertial Microcavitation
Jin Yang, Harry C. Cramer III, and Christian Franck
Abstract To constitutively characterize soft material large deformation properties at high loading rates (10
3
–10
8
s
−1
), we
recently developed an experimental technique called Inertial Microcavitation Rheometry (IMR). Here, inertial cavitation
bubbles are generated through a spatially focused pulsed laser, e.g., hydrogels, tissues, and various polymeric specimens. By
recording the spatiotemporally resolved bubble dynamics via high-speed videography, a combined experimental and theoretical investigation of single bubble cavitation in soft viscoelastic materials has been conducted, where we observe evidence
of strain localization and surface instabilities near the bubble wall during bubble expansion and collapse. We provide direct
experimental observation of how strain localization can lead to various types of surface instabilities within a gel- like soft
material giving rise to kink, wrinkle, and crease patterns. These types of dynamic rugae patterns and associated strain concentrations might be of significant interest in medical and engineering applications that utilize or encounter microcavitation,
e.g., during ultrasound or laser surgeries, or traumatic brain injuries.
Keywords Inertial cavitation · Hydrogel · High strain-rate · Rugae instability · Crease
8.1 Introduction
Cavitation is a common phenomenon in many biological systems and medical applications [1, 2]. For example, inertial cavitation can cause serious damage to soft tissues and cells [3–5]. On the other side, when harnessed carefully, bubble cavitation
can be used beneficially in many surgical and medical procedures, for example, in cataract laser surgery, lithotripsy, and
histotripsy applications [6, 7]. In addition, well-controlled laser or ultrasound-induced cavitation provides an effective
method for characterizing soft material viscoelastic properties at extremely high strain-rates on the order of O(10
3
)–O(10
8
)
s
−1
. Recently, we developed an experimental technique called Inertial Microcavitation Rheometry (IMR) [8–10]. Here, inertial cavitation bubbles are generated through a spatially focused pulsed laser inside a soft material of interest. By recording
the spatiotemporally resolved bubble dynamics via high-speed videography, a combined experimental and theoretical investigation of single bubble cavitation in soft viscoelastic materials has been conducted. During bubble expansion-collapse
cycles, we observe evidence of strain localization and surface instabilities near the bubble wall. These types of dynamic
rugae patterns and associated strain concentrations might be of significant interest in many medical and engineering applications that utilize or encounter microcavitation, e.g., ultrasound or laser surgeries, or traumatic brain injuries. In this extended
abstract, we will present some experimental results providing direct evidence of the existence of dynamic surface instabilities
during inertial cavitation.
In this chapter, first, we introduce our material preparation and experimental setup in Sects. 8.2 and 8.3. Then we show
and analyze our experimental results in Sect. 8.4. Finally, we present some conclusions in Sect. 8.5.
J. Yang (*) · C. Franck
Department of Mechanical Engineering, University of Wisconsin- Madison, Madison, WI, USA
e-mail: jyang526@wisc.edu; cfranck@wisc.edu
H. C. Cramer III
School of Engineering, Brown University, Providence, RI, USA
Center for Biomedical Engineering, Brown University, Providence, RI, USA
e-mail: harry_cramer@brown.edu