Soft Matter Blog

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.

Dr Lee A. Fielding (MRSC, MIMMM, FHEA) is a Senior Lecturer in Polymer Chemistry in the Department of Materials at The University of Manchester and his research group is based in the Sustainable Materials Innovation Hub within the Henry Royce Institute, where he is currently the Research Area Lead for Chemical Materials Design. He obtained an MChem in Chemistry from The University of Sheffield in 2008, which was followed by a PhD in 2012 from the same institution with Professor Steven P. Armes. He then worked as a Postdoctoral Researcher before taking up a Lectureship at The University of Manchester in 2015, where he is currently the Director of Postgraduate Taught Studies for Materials Science and Engineering and Programme Co-ordinator for the MSc in Polymer Materials Science and Engineering (PMSE). He is a committee member of the Joint Colloids Group and his research primarily involves the design, synthesis and applications of polymers and polymer colloids including research into sustainable waterborne coatings and adhesives, self-assembled colloidal materials and polymer-based materials for biomedical diagnostics and regenerative medicine.

Find more about his work via:

Website: Fielding Lab

Twitter @lee_fielding

Read Lee Fielding’s Emerging Investigator article http://xlink.rsc.org/?doi=10.1039/D2SM01534J

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

Soft Matter is inherently interdisciplinary and a natural home for reporting research into the preparation and characterisation of hydrogel systems with improved strengths, tuneable functionalities, and responsive behaviour. It’s broad readership, reputation and the efficient publication process all make it a great place to publish our research.

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 the utilisation of new approaches to design polymer colloids and how they can be used to tackle interdisciplinary challenges or real-world problems. These challenges may be in developing advanced materials for a more sustainable society or for use in areas such as biomedical diagnostics or regenerative medicine.

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

As we transition towards a more sustainable society the development and adaptation of materials that are designed with sustainability in mind, whilst retaining or improving on functionality, is a huge challenge that raises a great deal of academic, industrial, and societal questions.

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

Take the time to build your network! It really helps to share and learn from each other’s experiences, begin identifying and developing shared research interests, and ultimately make friends who also work in your discipline. I did this in part through firstly attending, and then organising, early career events such as the annual recent appointees in polymer science (RAPS) and early career colloids (ECCo) meetings.

Dr. Moyuan Cao is currently a professor and principal investigator at the School of Materials Science and Engineering, Nankai University, China. He received his B. Eng. Degree (2010) and M. Sc. Degree (2013) in Macromolecular Science and Engineering from Zhejiang University, China. In 2016, he received his Ph.D. Degree in materials sciences under the supervision of Prof. Lei Jiang at Beihang University and the Chinese Academy of Sciences. He is also a member of Haihe Laboratory of Sustainable Chemical Transformations (Tianjin, China) and Smart Sensing Interdisciplinary Science Center of Nankai University. He has published over 60 peer-review papers in Matter, Adv. Mater., Mater. Horiz., Adv. Funct. Mater., etc. His citation number is over 4100 with an H-index of 35. He serves as an Editorial member of Frontiers in Chemistry, Polymers, Chinese Chemical Letters and is an Advisory Board member of Materials Horizons. His present scientific interests are focused on the design and the applications of bio-inspired asymmetrical interfaces for fluid manipulation, including (1) Self-propelled fluid delivery on open interfaces; (2) Bubble manipulation on hydrophobic slippery surfaces; (3) Janus structures with superwettability for novel applications.

Find out more about his work via:

Website: https://mse.nankai.edu.cn/cmy_en/list.htm

Read Moyuan Cao’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D2SM01547A

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

Even as an undergraduate student, I knew Soft Matter as an important journal in the field of polymers, interfaces and fluid dynamics. As a traditional journal, Soft Matter has published a lot of theoretical and scientific papers which can serve as inspiration and provide references for analyzing related experimental phenomena. When my students feel puzzled about some theoretical examples to explain a result, I may ask them to find some references in Soft Matter. For this review article we published, lubricant-infused slippery surfaces have been considered as a new and useful functional interface for versatile applications (1). The design, mechanism, and applications of such interfaces are of interest, and the related information can be helpful for researchers in the fields of materials chemistry, physics, interfacial science and other areas. Therefore, in my opinion, such topics that combine theory and applications are suitable for Soft Matter.

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

Our research is focused on fluid-manipulating interfaces: most of our ideas are inspired by nature, so we call them bioinspired interfaces. The first question in such research is to understand the natural evolution logic for special functions. Why does an organism adopt such complex structures for controlling fluid manipulation such as drinking and sweating?  After understanding this logic, artificial interfaces with similar or improved performance can be designed, such as the lotus-like Janus floater (2), the Pistia-inspired 3D floater (3), and the cactus-inspired fog collector (4). The most exciting part of bioinspired research is finally knowing nature’s secret and unraveling it with artificial design. It makes me feel “Nature, I know you”, just like the saying “Man thinks, God laughs”. We might not totally understand the inner logic of even one simple creature, but what we can do is illustrate one little aspect of nature’s design. The most challenging part of our research is knowing how to bridge fundamental research with practical applications. Although we have designed and fabricated lots of materials for fluid manipulation, the practical application of such materials in industrial processes is still lacking. We believe that our materials can be useful and valuable in our daily life. However, it is a very difficult and complicated process for us to transform fundamental results. We hope that we can propose one or two products relating to fluid manipulating interfaces some day.

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

The most important question in the field of my research is why nature has an ultrahigh efficiency of mass transfer. Compared with our modern techniques, nature has a lot of advantages in mass transfer, energy conversion, information storage etc. With respect to fluid manipulation, nature’s strategy is always fantastic. Can you believe that the tiny proboscis of a butterfly or a mosquito sucks viscous liquid without blocking? Do you know how a tall tree can continuously uplift fluid to over 100m high? The ultrahigh efficiency and the ultralow energy consumption of nature’s design is both mysterious and enlightening for us.

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

Choose your own adventure, make your own brand, and stick with it…..

References

(1) Xinsheng Wang, Haoyu Bai, Zhe Li, Moyuan Cao*; Fluid manipulation via multifunctional lubricant infused slippery surfaces: principle, design and applications, Soft Matter, 2023, D2SM01547A.

(2) Yuyan Zhao, Cunming Yu, Hao Lan, Moyuan Cao*, Lei Jiang*; Improved interfacial floatability of superhydrophobic/superhydrophilic Janus sheet inspired by lotus leaf, Advanced Functional Materials, 2017, 27: 1701466.

(3) Yifan Yang, Haoyu Bai, Muqian Li, Zhe Li, Xinsheng Wang, Pengwei Wang*, Moyuan Cao*; An interfacial floating tumbler with a penetrable structure and Janus wettability inspired by Pistia stratiotes, Materials Horizons, 2022, 9: 1888.

(4) Haoyu Bai, Tianhong Zhao, Xinsheng Wang, Yuchen Wu, Kan Li, Cunming Yu*, Lei Jiang, Moyuan Cao*; Cactus kirigami for efficient fog harvesting: simplifying a 3D cactus into 2D paper art, Journal of Materials Chemistry A, 2020, 8: 13452.

Jinhye Bae is an Assistant Professor in the Department of NanoEngineering at the University of California, San Diego. She received her Ph.D. in Polymer Science and Engineering at the University of Massachusetts Amherst in 2015, then worked in the School of Engineering and Applied Sciences at Harvard University as a Postdoctoral Fellow. Her research focuses on understanding the physical and chemical properties of polymeric materials to program their shape reconfiguration and responsiveness. Her research interests also include the integration of material characteristics into new structural design and fabrication approaches for applications in biomedical devices, soft robotics, actuators, and sensors. She has received several awards including the American Chemical Society Petroleum Research Fund Doctoral New Investigator Award (2021) and the KIChE President Young Investigator Award (2021).

Find out more about her work via:

Group website: https://jbae.eng.ucsd.edu

Twitter: @jinhye_bae

Linkedin: https://www.linkedin.com/in/jinhye-bae-1388b01a/  

Read Jinhye Bae’s Emerging Investigator article http://xlink.rsc.org/?doi=10.1039/D2SM01104B

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

Soft Matter has been a go-to journal for publishing research on the topic of soft materials as it broadly covers the fields such as chemistry, physics, materials engineering, and biology, and includes experimental, theoretical, and computational research. Our research focuses on programmable shape reconfiguration and responsiveness of soft materials by the integration of functional materials in a controllable manner or their structural designs. I feel that Soft Matter is an excellent venue to disseminate our findings on this topic to a broad audience.

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

The most exciting aspect of our research is elucidating new fabrication-structure-property relationships of stimuli-responsive soft materials through the use of advanced small-scale fabrication techniques at the micro and nano-scales. I think this question can be the most challenging to address. To tackle this, we work on understanding the differences in physical and mechanical behaviors and the responsiveness of these materials at different scales, which can open up new possibilities for their application in areas such as micro-actuators, biomimetic systems, and biomedical applications.

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

In my opinion, important questions in the field of stimuli-responsive soft materials research include how much a system can be scaled down while maintaining its characteristics without becoming fragile, and how stimuli-responsive synthetic materials can be applied to engineer living systems by understanding their living/nonliving interface. In the longer term, understanding such questions will allow us to predict their properties and responsiveness in non-equilibrium conditions thus creating trainable and intelligent soft materials systems.

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

Do not hesitate to open up discussions with colleagues, mentors, and students – it can help you think outside the box. I have found that even failed trials or unexpected results can lead to exciting ideas, so be sure to set aside time to meet with your students and carefully listen to their observations and thoughts.

Dr. Siddhartha Das is currently an Associate Professor in the Department of Mechanical Engineering, University of Maryland, College Park. His research focuses on the science and engineering of soft and polymeric materials, interfacial transport, and small-scale fluid mechanics for fundamental discoveries (in ion dynamics at soft interfaces, liquid transport in soft-material-functionalized nanochannels, drop behavior on squishy surfaces, and charge-driven nanoparticle-lipid-bilayer interactions) and cutting-edge applications (in additive manufacturing). He received his B.S. (or B-Tech.) and Ph.D. from the Indian Institute of Technology Kharagpur. He has published more than 170 journal papers in world-renowned journals (such as Nature Materials, Science Advances, PNAS, PRL, JACS, APL, Matter, Nucleic Acid Research, Nature Communications, Advanced Materials, and ACS Nano) and has received numerous awards and accolades (including promotion to Associate Professorship with an early tenure, election as a Fellow to the Royal Society of Chemistry, Institute of Physics, U.K., and Institution of Engineering and Technology, U.K., Junior Faculty Outstanding Research Award of the A. James Clark School of Engineering, selection to contribute in the emerging investigator issue of the journal Physical Chemistry Chemical Physics and Soft Matter, IIT Kharagpur Young Alumni Achiever Award, Hind Rattan award).

Find out more about his work via his group’s Twitter @smiel_umd

Read Siddhartha Das’s Emerging Investigator article: http://xlink.rsc.org/?doi=10.1039/D2SM00997H

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

Soft Matter is a wonderful venue for publishing exciting new works on soft materials, complex fluids, biological systems, etc. The present paper uses machine learning to unravel new characteristics of the water-water hydrogen bonds (HBs) inside the charged polyelectrolyte (PE) brush layer described using all-atom molecular dynamics (MD) simulations.  Papers in these areas of polymer systems and machine learning applications of soft matter systems have been extensively published in Soft Matter due to the sheer reach and the visibility of the journal to the soft matter and polymer science community. In that respect, I consider Soft Matter to be a perfect place to publish my research.

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

A big focus of my present research is to explore the properties and behaviors of polyelectrolyte brushes and brush-supported water molecules and ions using all-atom molecular dynamics simulations. Such all-atom simulations have been scarcely applied for PE brushes and my group was among the first to do so. Several of my previous papers have unraveled, for the first time, detailed properties and behaviors of PE-brush-supported water molecules and counterions. This present paper employs machine learning (ML) to take this endeavor further: ML enables us to identify structures and properties of water molecules and counterions inside the brush layer that are distinctly different from that outside the brush layer. In that way, we converge upon new definitions of water and ion properties inside the brush layer (e.g., the conditions that define water-water hydrogen bonds inside the brush layer). This is what I am really excited about at this moment: how the interplay of highly resolved atomistic simulations and machine learning algorithms enable us to obtain hitherto unknown properties of water and ions inside a PE brush layer. Such findings will lead to a paradigm shift of the way in which PE brushes are viewed by the research community: these brushes, henceforth, will be considered as a medium that triggers very rich water and ion science.

The most challenging part of my research is to connect these very interesting discoveries on PE-brush-supported ions and water to a larger scale description of the PE brush systems. Such a thing could possibly be accomplished by a multi-scale description of the PE brushes (where all-atom MD simulations and coarse-grained MD simulations are coupled) and ML methods will be useful for not only achieving such coupling but also for performing the sampling over a much larger time window.

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

PE brushes have great potential for a multitude of applications in medical, chemical, engineering, and diagnostic sciences. The central tenet of these applications is the responsiveness of such brushes to environmental stimuli. These responses strongly depend on the structure of the PE brushes and the behavior and properties of the brush-supported water molecules and counterions. Given that we are now able to explore unprecedented atomistic details of such brush-supported water and ions, the most important questions to be answered in the field are as follows:

1. How the properties of such brush-supported water and ion properties can be regulated for ensuring desired responsiveness of the brushes (and hence achieving unprecedented efficiency in certain established brush-driven applications and develop new applications of brush-based systems) to environmental stimuli?
2. How to model reactive brushes and their responses to environmental stimuli?
3. How liquid and ion transport take place at such brush-grafted interfaces?
4. How machine learning can improve our predictions of all these effects?

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

For early-career scientists, my one piece of career-related advice will be to have fun in doing new things in research. Very often the burden of the tenure-track system (or similar conditions) forces early career scientists to do research on things that are safer and on which they have previous experience. However, in that way, the fun of discovering new things and contributing to new areas goes completely missing and makes the life of early career scientists more stressful and the work less exciting.