Soft Matter Blog

Dr. Scott Tsai is the Director of the Graduate Program in Biomedical Engineering, and a Professor in the Department of Mechanical and Industrial Engineering at Toronto Metropolitan University. His undergraduate training in Mechanical Engineering is from the University of Toronto, and his masters and PhD degrees in Engineering Sciences are from Harvard University. Dr. Tsai’s laboratory specializes in droplet and bubble microfluidics. His group also collaborates actively with hospital researchers to implement these technologies in medical applications related to lung disease and prostate cancer. Dr. Tsai is a recipient of the United States’ Fulbright Visiting Research Chair Award, Government of Ontario’s Early Career Researcher Award, and Toronto Metropolitan University’s Deans’ Teaching Award. 

Read Scott Tsai’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D3SM00380A

Find out more about his work via:

Twitter: https://twitter.com/scottshtsai

LinkedIn: https://www.linkedin.com/in/scott-tsai-2946082b/

Google Scholar: https://scholar.google.ca/citations?user=STD2oDMAAAAJ&hl=en

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

I am excited about the prospects of utilizing nanobubbles as next-generation ultrasound imaging contrast agents and targeted drug delivery vehicles. While microbubbles have already been approved and used as contrast agents, nanobubbles, which are about a thousand times smaller, have unique advantages in a number of applications, and are only beginning to be used in applications in the last few years. One of the most challenging aspects of nanobubble research has been to make nanobubbles that have a consistent size, which we are helping to improve with microfluidics. The most challenging aspects now are to generate the nanobubbles at high concentrations microfluidically. This is difficult to do, but once achieved, enables many more impactful applications. 

Can you share one piece of career-related advice or wisdom with other early career scientists?

I think it is important for early career scientists to have a mentor who is established and experienced. There are many complex issues that independent scientists need to navigate, from research funding to campus politics. Most scientists are not trained to deal with these matters, so I have found that having a mentor (who preferably is at the same institution) has been extremely helpful.

Dr. Xueju ‘‘Sophie’’ Wang is currently an Assistant Professor in the Department of Materials Science and Engineering and the Institute of Materials Science at the University of Connecticut. She obtained her Ph.D. degree in Mechanical Engineering at the Georgia Institute of Technology in 2016 and was a postdoctoral scholar at Northwestern University from 2016 to 2018. Her research interests lie in the intersection of active materials, mechanics, and functional structures for applications ranging from soft robotics to flexible electronics. She is the recipient of the NSF CAREER Award, NIH Trailblazer Award, Extreme Mechanics Letters (EML) Young Investigator Award, ACS PMSE Young Investigator Award, and ASME ORR Early Career Award in recognition of her significant contributions to her research field.

Read Xueju Wang’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D3SM00563A

Find out more about her work via:

Group Website: https://www.wangresearchlab.com/

Twitter: @XuejuW

How do you feel about Soft Matter as a place to publish research on this topic?

Soft Matter is a well-established journal for reporting significant advances in interdisciplinary soft matter research, especially at the interface between chemistry, materials science, and biology. It is one of my favorite journals because of the rigorous review that helps improve our work and the efficient publication process. In addition, with its broad readership, it offers a great platform to disseminate our research findings and maximize the impact of our work.

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

I am very excited about developing soft, pressure-tolerant ocean sensors and integrating them with soft robots for next-generation ocean exploration. Traditional ocean sensors usually require bulky pressure chambers to protect the electronics from damage in harsh ocean environments. Our developed soft ocean sensors, which are made of metal thin films embedded in soft incompressible materials for monitoring ocean temperature, pressure, and salinity, can eliminate the need for pressure chambers and therefore significantly reduce the power supply and the footprint of the sensor. In addition, it has significantly extended the application of current flexible electronics in the low-pressure regime to large hydrostatic-pressure environments for the first time. The most challenging part of this research is the robustness and reliable operation of the developed sensors in harsh, complicated ocean environments, where pressure tolerance and encapsulation under large hydrostatic pressure and salinity environments are critical.

In your opinion, what are the most important questions to be asked/answered in this field of research?

I think developing soft bio-inspired intelligent systems that can integrate sensing, control, and actuation within one system is very important to safely interact and adapt to the surroundings for applications including ocean exploration, search and rescue, and many others. In addition, efficient power supply especially for flexible miniaturized electronics is another important question to answer.

Can you share one piece of career-related advice or wisdom with other early career scientists?

One piece of advice that I would like to share is to work on research directions that you are really excited about. Although there may be some potential risks, your interest will really drive you to address the challenges and it would be paid off eventually.

Dr. Dongshi GUAN is a Professor at the Institute of Mechanics at the Chinese Academy of Sciences and a Professor at the School of Engineering Science at the University of Chinese Academy of Sciences. He received his PhD in Physics from Hong Kong University of Science and Technology (HKUST) in 2016. During 2014-2015, Guan was a Visiting Scholar at the Laboratoire Interdisciplinaire de Physique in Grenoble, France. After graduation, he was a Postdoctoral Fellow in the Department of Physics at HKUST, and subsequently became a Research Assistant Professor and was honored with an IAS Junior Fellowship in 2017. After joining the Institute of Mechanics in 2019, his research group has focused on experimental investigation of micro- and nano-scale liquids at interfaces in soft and living matter systems, such as dynamics of moving contact line, mechanism of phase-separated protein droplets, and mechanical properties and active behavior of living cells and tissues.

Read Dongshi Guan’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D3SM00592E

How do you feel about Soft Matter as a place to publish research on this topic?

Soft Matter provides a unique forum for communicating significant advances in interdisciplinary soft matter research and is well-regarded within the scientific community. It is a great place to publish our Emerging Investigator article on the mechanical response and relaxation behavior of hydrogels. In the article, we report systematic atomic-force-microscopy (AFM) measurements of stress relaxation and crossover behavior of agarose hydrogels. By examining the interplay between poroelasticity and viscoelasticity in hydrogels at the micron level, we can gain insights into the mechanical response of living cells and tissues when subjected to deformation. This work thus represents a breakthrough in our understanding of the mechanical response and relaxation behavior of soft hydrogels and establishes a meaningful connection between soft matter physics and biological science.

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

Being trained as a soft matter physicist, I am excited about my research gradually became involved with interdisciplinary research on biological systems, which would help unravel the mysteries of life. Although science is often taught as if the various disciplines were clearly separate, exciting things can happen when the boundaries blur. The study of soft matter is one emerging field that has received increasing interdisciplinary attention from researchers in physics, chemistry, mechanical engineering, and life science. Living cells, as particular forms of soft material, exhibit unique mechanical properties closely related to their activities, functions, and health. A major challenge to the experimental study is that the cells are extremely soft, delicate, and surrounded by a liquid medium. In my research, I use the AFM as a microscopic “finger” to detect soft material surfaces and living matter, such as fluid interfaces, hydrogels, cells and tissues, to study their mechanical properties and underlying physics. I aim to develop new techniques for studying micro- and nano-scale liquids and cells at interfaces and better understand living matter from a physicist’s viewpoint.

In your opinion, what are the most important questions to be asked/answered in this field of research?

Accurately measuring the mechanical properties of living cells is crucial in understanding their microscopic origins and how they relate to cell responses and functions. However, living cells have complex structures and exhibit a variety of viscoelastic behaviors at different scales. Hydrogels share many similarities with cells, making them an ideal model to investigate the relaxation and crossover behavior of living matter. In our previous work, we obtained a unified quantitative description of the compressive modulus of individual living cells and provided a digital spectrum of mechanical readouts that are closely linked to the hierarchical structure and active stress of living cells. In this Emerging Investigator article, we further prove this unified description by relatively simple polymeric systems and demonstrate that hydrogels can serve as a model to investigate the relaxation and crossover behavior of living matter.

Can you share one piece of career-related advice or wisdom with other early career scientists?

My advice for early career scientists in the field of soft matter is to actively build interdisciplinary network and collaborate with peers and experts in different fields. Working together with scientists from different fields can bring about fresh perspectives and approaches to tackle complex scientific issues. Furthermore, seek out mentors who can offer guidance and support as you navigate your early career. I greatly benefit from discussions with Prof. Penger Tong, Prof. Elisabeth Charlaix, and Prof. Masao Doi.

Find out more about his work via: https://people.ucas.edu.cn/~guandongshi?language=en

Dmitry A. Fedosov received his Bachelor’s degree in mathematics from Novosibirsk State University, Novosibirsk, Russia in 2002. After earning a MS degree in aerospace engineering from the Pennsylvania State University in 2004, he moved to Brown University, where he pursued a PhD degree in applied mathematics. Dmitry received a MS degree in applied mathematics in 2007 and his PhD in 2010. His thesis work was on multiscale modelling of blood flow and polymeric soft matter systems. His thesis work was recognized with the 2011 Nicholas Metropolis Award for outstanding doctoral thesis work in computational physics from the American Physical Society. After completing his PhD, Dmitry moved to Forschungszentrum Juelich in Germany, and received the Sofja Kovalevskaja Award from the Humboldt foundation to build up an independent research group. Currently, he continues to work as a group leader at Forschungszentrum Juelich with a research focus on non-equilibrium physics, including various complex systems in biophysics and active matter.

Read Dmitry Fedosov’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D3SM00004D

How do you feel about Soft Matter as a place to publish research on this topic?

Soft Matter is a good match for the research on active matter systems, as I feel it reaches out to the research community interested in this topic.

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

I am fascinated by active non-equilibrium systems which can exhibit very complex structures, dynamics, and responses to various external conditions and manipulations. Even though diverse properties of these systems make their investigation very challenging, they also lead to great opportunities for finding novel physical mechanisms and for using these systems in many technological and biomedical applications.

In your opinion, what are the most important questions to be asked/answered in this field of research?

I think one of the most important questions is the emergence of complex structures, dynamics, and responses of active soft systems from interactions between their internal simple constituents. Can we explain, tune, and control the behaviour of active systems?

Can you share one piece of career-related advice or wisdom with other early career scientists?

Be persistent and follow your ideas and dreams no matter what difficulties you meet on the way. Eventually, it will pay off in some expected or unexpected way.

Bhuvnesh Bharti is an Anding Endowed Associate Professor in the Cain Department of Chemical Engineering at Louisiana State University. He received his B.S. (Hons. School) and M.S. (Hons. School) from Panjab University Chandigarh, India. He obtained his PhD at Technische Universität Berlin, Germany in 2012, which was followed by postdoctoral research at Shinshu University and North Carolina State University. Bhuvnesh is the recipient of several awards including Springer Theses Award (2014), NSF-CAREER Award (2020) and LSU Rising Faculty Research Award (2021). His research group investigates structure-property-function relationships in colloidal dispersions and develops methodologies to program their equilibrium and non-equilibrium behaviours. His present research interests include active colloids, directed assembly, and fundamental investigations on environmental colloidal pollutants such as microplastics.

Find more about his work via:

Group website: https://faculty.lsu.edu/bbhartigroup/index.php

LinkedIn: www.linkedin.com/in/b-bharti 

Read Bhuvnesh Bharti’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D3SM00354J

How do you feel about Soft Matter as a place to publish research on this topic?                                                                                        

We are always excited to submit our work to Soft Matter. It is a reputable, and well-established avenue for publishing our research. With its wide readership invested in soft matter science and related disciplines, it offers an invaluable platform to maximize the visibility and impact of our work. I believe that Soft Matter plays an important role in advancing the field as a whole by providing us a platform to contribute to the collective understanding of soft materials and their properties.

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

Currently, one of the major thrusts in our research group is on investigating the behaviour of colloids driven by external electric and magnetic fields. We believe that field-driven colloidal matter occupies an intriguing intersection between traditional synthetic materials and the dynamic machinery found in out-of-equilibrium biological systems. The ability to energize colloidal particles using external fields provides an opportunity to uncover the fundamental principles underlying the assembly and functionality of biomaterials. This knowledge can be harnessed to design functional materials with customizable physicochemical properties. However, the research area of field-driven colloids presents several challenges that require attention to achieve a comprehensive understanding of these systems. Key among these challenges, from my perspective, is the precise control of colloidal structure and dynamics in three-dimensional space, as well as predicting their complex behaviours and emergent properties. Additionally, practical applications necessitate addressing scalability, robustness, and controlled responses in complex environments. Successfully tackling these challenges will advance our understanding of field-driven colloids and unlock their potential applications.

In your opinion, what are the most important questions to be asked/answered in this field of research?

In our opinion, the single most important question that needs to be addressed in the area of field-driven colloids is: “What are the mechanisms and principles governing the dynamic self-assembly and collective behaviour of field-driven colloidal particles in three-dimensional space?” This question goes beyond surface-level understanding and dives into the intricate processes that dictate how external fields influence the motion, assembly, and interactions of colloidal particles in complex 3D environments. To answer this question, our ongoing research focuses on investigating the intricate interplay between external fields and colloidal dispersions, seeking to unravel the underlying mechanisms that govern their structure and dynamics. We are also exploring the complex interactions between particles themselves, as well as their interactions with the applied field, considering factors such as particle shape, size, and surface properties. By addressing these challenges and gaining a deeper understanding of the principles at play in 3D space, we aim to unlock the full potential of field-driven colloids and open up exciting possibilities for transformative applications in various scientific and technological domains.

Can you share one piece of career-related advice or wisdom with other early career scientists?

Starting an independent research career and establishing a research lab can be intimidating. In my opinion, it’s crucial to prioritize sustainability in our scientific careers. This means focusing not only on research but also educating and mentoring young minds along with maintaining a healthy work-life balance. A successful research career involves more than publishing articles and securing grants—it also encompasses mentoring, graduate student training, and education. While achieving work-life balance is challenging, it’s essential to make an effort to maintain this equilibrium for the well-being of yourself and your loved ones.

Dr Stefan Guldin is Professor of Adaptive & Responsive Nanomaterials and Deputy Head (Enterprise) of the Department of Chemical Engineering at University College London. He studied Physics at Karlsruhe Institute of Technology (2003-05) and the Technical University of Munich (2005-08) and graduated with a PhD from the University of Cambridge in 2012 (Advisor: Prof Ulli Steiner; thesis title: Inorganic nanoarchitectures by organic self-assembly). Subsequently, Dr Guldin carried out postdoctoral research as a scholar of the German Academy of Sciences at EPFL (Advisor: Prof Francesco Stellacci) before taking up his current position in 2015. His research interests include the study of material formation on the nanoscale by molecular self-assembly, creation of adaptive and responsive materials architectures and translation into real-world applications, ranging from chemical sensors and biomedical diagnostics to electrochemical devices and optical coatings. For his work, Dr Guldin has received awards by the Institute of Physics, German Academy of Sciences, the German National Academic Foundation, Springer Publishing and the European Materials Research Society. He is co-founder of the biomed start-up Vesynta, which is devoted to the development of companion drug monitoring solutions for personalised medicine with currently 6 full-time employees. His educational platform qTLC.app, which enables researchers to conduct analytical chemistry with a smartphone, is used in 47 countries across 6 continents.

Find more about Stefan’s work via:

Website: www.ucl.ac.uk/responsive-nanomaterials

Twitter: @AdReNa_Lab

Read Stefan Guldin’s Emerging Investigator article http://xlink.rsc.org/?doi=10.1039/D2SM01348G

How do you feel about Soft Matter as a place to publish research on this topic?

While there is such a broad choice now, Soft Matter remains one of my favourite journals. The reason is quite simple – its quality of peer review remains unmatched. Every article that has gone through the publication process with Soft Matter significantly improved in response to the reviewers’ comments. The depth of responses and enthusiasm for science that often resonates from Soft Matter reviewers shows that the journal is able to recruit some of the most knowledgeable subject experts that are willing to give their time and brain power to the community.

Can you share one piece of career-related advice or wisdom with other early career scientists?

When building a research group from scratch, it can be tempting to go after every opportunity for growth. It is very important that you are creating synergies between your group members and building up a core expertise in specific materials systems and characterisation techniques. This will allow you to build your own profile and become attractive for collaborations. While you may be perfectly able to go very broad even early on, this will rarely be recognised by your community.

Rahul Mangal is presently an Associate Professor in the department of Chemical Engineering at Indian Institute of Technology (IIT) Kanpur. He received his PhD in 2016 from Cornell University on structural and dynamical investigation of nanoparticle polymer composites. Subsequently he did a Post Doc at University of Wisconsin Madison. After joining IIT Kanpur in 2017, his research group has been focusing on experimental investigation of several fundamental problems in areas such as Active Soft Matter, Polymers and their composites and Liquid Crystals. Rahul’s research contributions have been rewarded with several accolades including Indian National Academy of Engineering (INAE) Young Engineering Award 2020 and 1979 Batch Young Researcher fellowship by IIT Kanpur. Additionally, he serves on the Editorial Advisory Board of ACS Applied Polymer Physics.

Find more about Rahul’s work via

Twitter: @mangalr

Read Rahul Mangal’s Emerging Investigator article http://xlink.rsc.org/?doi=10.1039/D3SM00228D

How do you feel about Soft Matter as a place to publish research on this topic?

Ever since I started my academic career, I have held Soft Matter in high esteem because of its broad readership and interdisciplinary authorship in fields such as colloids and interfaces, polymers, emulsions etc. Furthermore, Soft Matter is known to have a rigorous peer-review process enabling it to publish high-quality research which enjoys a wide reach and strong reputation in the scientific community. For these reasons I strongly consider Soft Matter to be an excellent platform to showcase our novel findings of deforming active motion of droplets in a viscoelastic environment.

What aspect of your work are you most excited about at the moment and what do you find most challenging about your research?

Artificially propelling droplets are very exciting active soft matter systems which have become a captivating subject of scientific interest due to their potential to emulate biological motion and function as advanced cargo transporters. However, the current understanding of their motion is mostly confined to uncomplicated Newtonian environments. Presently, we are excited that through comprehensive investigations, our recent research has delved into the behaviour of these droplets in non-Newtonian environments leading to the discovery of several novel phenomena, including the deforming active motion presented in this study. Considering that these non-equilibrium systems are rather new, several fundamental aspects about their behaviour are not known yet, therefore, the understanding of the complex underlying physics behind their intriguing phenomena remains a major challenge.

In your opinion, what are the most important questions to be asked/answered in this field of research?

In my opinion, a crucial question that still requires an answer is how we can achieve complete command over artificial swimmers to utilize them as efficient cargo carriers and diagnostic agents in microscopic environments. To tackle this issue, current scientific endeavours are focused on comprehending the behaviour of these swimmers in diverse and intricate settings, with the ultimate goal of enabling their deliberate navigation.

Can you share one piece of career-related advice or wisdom with other early career scientists?

When starting out as a new academic, it is common to receive numerous advice from various sources. However, the most effective approach is to stay true to our own interests and zeal while keeping things uncomplicated. Initiating a new research group and exploring uncharted territory can be daunting, but perseverance typically pays off in the end.

Tal Cohen is an Associate Professor at MIT. She joined the Department of Civil & Environmental Engineering in November 2016 and has a joint appointment in the Department of Mechanical Engineering. She received both her MSc and PhD degrees in Aerospace Engineering at the Technion in Israel. Following her graduate studies, Tal was a postdoctoral fellow for two years at the Department of Mechanical Engineering at MIT and continued for an additional postdoctoral period at the School of Engineering and Applied Sciences at Harvard University. She received the ONR young investigator award and the NSF CAREER award in 2020, and the ARO young investigator award in 2019. Earlier awards include the MIT-Technion postdoctoral fellowship, and the Zonta International Amelia Earhart Fellowship. Her research is broadly aimed at understanding the nonlinear mechanical behavior and constitutive sensitivity of solids. This includes behavior under extreme loading conditions, involving propagation of shock waves and dynamic cavitation, material instabilities, and chemo-mechanically coupled phenomena, such as material growth. 

Find more about her work via:

Website: http://tal-cohen.wixsite.com/website

Twitter: @CohenMechGroup

Read Tal Cohen’s Emerging Investigator article http://xlink.rsc.org/?doi=10.1039/D2SM01675C

Our current research

We are interested in understanding how materials behave when they are pushed to their extremes; whether by imposing large deformations, by applying dynamic loading conditions, or by growth. Closely related to experimental observations, our research exploits analogy with related fields and accounts for complex material response, with the overarching goal to derive theoretical models that can significantly affect our understanding of the observed phenomena, but are still simple enough to be applied in design or characterization of materials. We are a theoretical group with an experimental lab that by basic material fabrication and mechanical testing allows us to make observations and to validate our theories.