Prof. Srinivasa R. Raghavan

Patrick & Marguerite Sung Professor
Dept. of Chemical & Biomolecular Engineering
University of Maryland, College Park

Office: 1227C Chem-Nuc Building

Phone: (301) 405-8164

Email:  sraghava@umd.edu

Bio    |    CV     |    Google Scholar

SRR
Group Photo: 2021

Group Members

PhD Students
Sohyun Ahn
Nikhil Subraveti
Hema Choudhary
Leah Borden
Faraz Burni
Wenhao Xu
Medha Rath
MS Students
sairam ganesh
uma kokilepersaud
Undergrads
Morine Nader
Christine Zhou
Jillian Schwartz
Sebastian Peters

Featured Group Member 1

Congratulations to Sohyun! She defended her Ph.D. in Aug 2021 and is set to join Novavax Inc. Sohyun was co-advised by Prof. Bill Bentley from BioE – so she got to work with both capsules and microbes! Her excellent paper on capsules with embedded cells was published recently in ACS-AMI.

More on Sohyun >

sohyun ahn

Sohyun Ahn

Featured Group Member 2

Congratulations to Leah! Her paper on electroadhesion of hydrogels to animal tissues was published recently in Nature Communications. Leah has been awarded a GAANN Fellowship and the Sengers Scholarship from ChBE.

More on Leah >

leah borden

Leah Borden

Featured Group Member 3

Congratulations to Hema! Her study on a novel class of foams to stop bleeding from serious injuries was recently published in ACS-AMI. Hema is a winner of the Sengers Scholarship from ChBE.

More on Hema >

hema choudhary

Hema Choudhary

Featured Group Member 4

Congratulations to Nikhil! His innovative approach to making a protective “skin” around any hydrogel was recently published in ACS-AMI. Nikhil has been awarded the Sengers Scholarship from ChBE.

More on Nikhil >

nikhil subraveti

Nikhil Subraveti

Recent News 1

An invention from our lab to stop bleeding has reached the market! The product is made by Medcura Inc., which is run by our alum, Dr. Matt Dowling.

See: “Scrape? Cut? Seal it with game-changing product created at UMD“. This product shows how “a fundamental discovery in the lab…can become a life-saving technology“.

Recent News 2

Leah’s recent discovery may be a significant one! We wrote a blog post about it at the Nature Bioeng. Community site.

Recent News 3

After a long gap, we went for group lunch in July 2021 to celebrate graduations. Congrats to Sairam and Futoon!

Recent News 4

Our lab has joined Twitter! Follow us @Complex_fluids to get the latest updates on our research.

What We Do

We create and invent new materials with unusual or exceptional properties. Read an interview with Prof. Raghavan…

The materials we create are usually soft solids or viscous fluids. We try to tailor their mechanical and flow properties. More…

Our specialty is “smart” materials, whose properties can be switched (by light, heat, electricity, etc.). More…

Our inventions often draw inspiration from nature at various length scales (macro, micro, nano). More…

We emphasize simplicity in our work. That is, we try to find simple routes to new materials using cheap ingredients. More…

Our scientific focus is on discovering the rules for molecular self-assembly into various nanoscale structures. More…

Techniques in which we have expertise include rheology, light scattering, and neutron scattering (SANS). More…

Res rheol

Research Areas Connected to the Group

Self-Assembly & Self-Organization

Colloid Science & Polymer Science

Nanotechnology & Bionanotechnology
Complex Fluids & Soft Matter
Nature-Inspired Materials

Featured Research: Electric Fields and Gels

Can we use electric fields to modulate soft materials? This is an area in which we have made several contributions. First, we developed electroformation as a way to make gels with precise shape in 3D (see above). It could allow tissues to be 3D-bioprinted without the need for a printer. Next, we have discovered electroadhesion, which allows gels to be adhered to biological tissues by applying a field. This could enable a simpler way to do surgeries in the future.

Applications of Interest to the Group

Biomaterials for stopping bleeding.
Environmentally benign clean-up of oil spills.
Drug delivery from nanoparticles switched on by light.
Soft and flexible batteries based on gels.
Simpler ways to do 3D-printing of tissues.

Featured Application: Stopping Bleeding

Stopping blood loss from wounds is crucial during surgeries and on the battlefield. We got into this area when we found a ‘hemostatic’ polymer that converts liquid blood into a gel (see above movie) by self-assembly. Thus, the polymer is able to stop bleeding from severe injuries. This technology won Invention of the Year at UMD in 2009, and since then has been patented and FDA-approved. Medcura, has brought this to the market in 2021.  

Did you know?

Three startup companies have been launched from our lab (Medcura, GripBoost, Prasidiux).

Did you know?

Our lab is credited with the first biomedical device invented at UMCP to receive FDA approval.

Did you know?

We developed the first food-grade dispersant that can be used to disperse oil spills into seawater.

Publications

Recent

1.      L. K. Borden, A. Gargava, S. R. Raghavan

Reversible electroadhesion of hydrogels to animal tissues for suture-less repair of cuts or tears.
Nature Communications, 12, 4419 (2021)

2.      S. H. Ahn, M. Rath,…W. Bentley, S. R. Raghavan

Single-step synthesis of alginate gels with a covalent shell: A simple way to protect encapsulated cells.
ACS Applied Materials & Interfaces, 13, 18432 (2021)

3.      S. N. Subraveti, S. R. Raghavan

A simple way to synthesize a protective “skin” around any hydrogel.
ACS Applied Materials & Interfaces, 13, 37645 (2021)

4.      H. Choudhary, M. Rudy,…S. R. Raghavan

Foams with enhanced rheology for stopping bleeding.
ACS Applied Materials & Interfaces, 13, 13958 (2021)

5.      N. R. Agrawal, F. Burni, V. John, S. R. Raghavan

Spontaneous formation of stable vesicles and vesicle-gels in polar organic solvents.
Langmuir, 37, 7955 (2021)

6.      B. C. Zarket, H. Wang,…S. R. Raghavan

Multilayer tubes that constrict, dilate, and curl in response to stimuli.
Soft Matter, 17, 4180 (2021)

7.      X. Yue, N. Subraveti, G. John, S. R. Raghavan

Phase-selective gelation of the water phase in an oil-water mixture.
Langmuir, 37, 8107 (2021)

Full List

Featured Recent Publication (1)

Electroadhesion of hydrogels to tissues for suture-less repair of cuts or tears. (Nature Communications, 2021)

We have discovered that cationic gels can be adhered to animal tissues by placing gel and tissue in an electric field (DC, 10 V) for 20 seconds. Applying the DC field with reversed polarity reverses the adhesion. Such electroadhesion can be used to seal cuts or tears in tissues. Our studies suggest that electroadhesion could be potentially used for performing surgery without the need for sutures.

Featured Classic Publication (1)

Superabsorbent hydrogels that are robust and highly stretchable. (Macromolecules, 2014)

Gels that absorb a lot of water are used in many products, such as diapers. This paper described a new superabsorbent gel that beat the world record for water-absorption – it could absorb 3000 times its weight in water. The gel could be easily made in the lab and it was also strong. Our recipe has been used by numerous researchers around the world.

Featured Recent Publication (2)

A simple way to synthesize a protective “skin” around any hydrogel. (ACS AMI, 2021)

Fruits and vegetables retain water because they are covered by a hydrophobic skin. In this paper, we devised a way to form a hydrophobic “skin” around hydrogels. The skin is thin, transparent and peelable. For a gel in water, the skin protects it from acids or microbes. For a gel exposed to air, the skin helps resist drying. Skin-covered gels could be used in robotics or other areas.

Featured Classic Publication (2)

An effective dispersant for oil spills based on food-grade amphiphiles. (Langmuir, 2014)

Oil spills on the ocean are usually cleared by spraying dispersants, but these can be toxic. We developed the first food-grade, non-toxic dispersant in this paper. It is based on lecithin (a lipid used in chocolate) and Tween 80 (a surfactant used in ice cream). The two work synergistically to form stable emulsions of crude oil in seawater.

Did you know?

Our research been featured in news stories by two local TV stations and in a program that aired on the Discovery Channel titled “Stephen Hawking Presents”.

Did you know?

More than 20 patents have been filed by UMD’s Office of Technology Commercialization based on inventions from our lab.

Did you know?

Inventions from our lab have been nominated thrice (in 2009, 2014, 2018) for UMD Invention of the Year. We won this award in 2009 for our blood-gelling polymer.