Faculty mentor: Prof. Darrin Pochan
Graduate mentor: Matt Langenstein

We are creating new nanoscale building blocks to build new polymeric materials. The building blocks are created with peptides that assemble in solution to form coiled coil bundles, called ‘bundlemers’. We use these building blocks to build interesting polymer chains as well as 2-dimensional sheets and 3-dimensional lattices with interesting mechanical properties as well as with inherent environmental compatibility being made out of amino acids. The project will involve learning peptide synthesis, molecular characterization, and solution assembly behavior with new peptide molecules designed to form bundlemers. With a solid understanding of the bundlemer assembly and solution behavior, these building blocks will be connected together in order to build new nanomaterials. Initial experiment in the degradation of these building blocks will be explored since all materials made from bundlemers have the exciting potential to degrade back into amino acids, an environmentally compatible set of molecules for green polymeric materials.

Faculty mentor: Prof. Christopher Kloxin
Graduate mentor: Josh Meisenhelter

Molecular structures found in nature are built upon common reoccurring substructural units, such as alpha helices and beta sheets; in contrast, most synthetic polymers lack such modular design and are less functionally sophisticated. This research project aims to develop a new approach for designing and preparing complex polymeric nanostructures using short peptide sequences that assemble into robust and well-defined coil-coil units called bundlemers. Here, we will implement new functionalization and crosslinking strategies towards realizing the bundlemer as a fundamental building block, or ‘molecular Lego’, to create complex targeted nanomaterials. The student working on this project will learn an array of small molecule and macromolecular synthetic methods (from non-natural amino acid synthesis to microwave solid phase peptide synthesis and polymer-peptide conjugations) and characterization techniques (from NMR and mass spec to scattering and TEM).

Faculty mentor: Prof. Xinqiao Jia
Graduate mentor: Hanyuan Gao

We are interested in developing peptide/polymer conjugates with unique assembly properties. The peptidic building blocks capable of forming coiled-coil 4-helical bundles (“bundlemer”) are produced via solid phase peptide synthesis and chemically addressable functional groups that participate in tetrazine ligation, an efficient, rapid and bioorthogonal cycloaddition reaction between tetrazines (Tz) and trans-cyclooctenes (TCO), are introduced after the peptide is cleaved from the solid support. Step growth polymerization is performed using bundlemers carrying complementary Tz and TCO functionalities in solution or at the water-oil interface. Conjugation of dihydrotetrazine (DHT), a Tz precursor that can be photocatalytically activated to Tz, on the side chain of the peptide enables post-polymerization modification of the peptide assemblies. Glycomimetic polymers (GMPs), with a polyacrylamide or polynorbornene backbone, saccharide side chains and a TCO end group, will be prepared employing living polymerization techniques. GMPs will be conjugated to the peptide assemblies via light triggered tetrazine ligation. The resultant peptide/polymer conjugates will be analyzed by circular dichroism (CD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), gel electrophoresis, size exclusion chromatography (SEC) and micromechanical testing.

Faculty mentor: Prof. LaShanda Korley (Research group)
Graduate mentor: Jessica Thomas

Hydrogels are an attractive material platform for applications in tissue engineering due to their general biocompatibility and ability to retain large amounts of water, thus mimicking some properties of natural tissues. However, synthetic hydrogels often lack the robust mechanical strength required for prolonged performance. This challenge may be mitigated by the use of high-strength additives to polymer networks to create composite gels. The goal of this project is to incorporate exceptionally rigid peptide rod assemblies into covalent networks to reinforce the polymer matrix while maintaining biocompatibility. Additionally, the inclusion of these nanoscale peptide coiled-coils allows for the introduction of stimuli responsive properties into the composite, as assembly is reversible through varying parameters such as temperature or pH. Covalent networks will be formed through a UV cure process, further expanding the utility of this system to additive manufacturing processing methods. Compression experiments will be performed in order to assess the effect of peptide rods on network strength. Differences in hydrogel morphology will be probed using scanning electron microscopy (SEM). These experiments will investigate the impact of a novel nanofiller on critical properties of hydrated networks.

Faculty mentor: Prof. Kristi Kiick (Research group)
Graduate mentor: Cristo Garcia and Sai Patkar

Themoresponsive polypeptides have many applications in the production of hydrogels, drug delivery systems, and actuating materials. One potential application of these polymers is as a responsive element in the assembly properties of rod-like materials. This summer project will explore the production of novel thermoresponsive polypeptides, and characterization of their solution and surface behavior, via spectroscopic and microscopy methods.

Faculty mentor: Prof. Eric Bloch (Research Group)
Graduate mentor: Mike Dworzak

Students on this project will use inorganic and coordination chemistry to prepare novel molecular structures for the synthesis of 1-, 2-, and 3-dimensional Peptide Active Materials. We will focus on the design and synthesis of coordination cages. Students will gain experience in organic synthesis, inorganic synthsis, and materials characterization.

Faculty mentor: Prof. April Kloxin (Research group)
Graduate mentor: TBD

Assemblying peptides inspired by Nature but that also go beyond naturally occurring sequences to integrate natural and non-natural functionalities provide great opportunities for the construction of materials with designed nanostructures and related multiscale properties. This summer project will focus on the design of bioinspired assemblying peptides, from synthesis and characterization to application.

Faculty mentor: Prof. Matt Doty (Research group)
Graduate mentor: Charles Ameyaw

One of the primary goals of the research by our IRG team is to develop hybrid materials that have optical and electronic functionality that goes beyond what can be achieved in any single material. We are particularly interested in the THz frequency regime, which is a portion of the electromagnetic spectrum in the extreme infrared that has many applications in biomedical imaging, security screening, and wireless communications. A big limitation on the use of THz frequencies is the lack of a single material platform that can provide all the functions required for a device. For example, III-V semiconductors such as GaAs can be very efficient sources and detectors of THz radiation, but they make very poor waveguides because they are transparent to THz radiation. In contrast, Topological Insulators are good at routing plasmons in the THz frequency range, but they are not good for generating or detecting these excitations. One goal for a hybrid material would be to combine generation, routing, and detection of THz frequency excitations in a single material platform. This project will focus on using ultrafast optical methods to measure the THz absorption and emission of hybrid materials synthesized by other members of our team. From this data we can understand the interactions between the constituents that make up the hybrid. The student will learn how to use ultrafast (pulsed) lasers, how to conduct optical experiments, how to analyze data, and how to work together as a team to understand the results.

Faculty mentor: Prof. Joshua Zide (Research group)
Graduate mentor: Wilder Acuna

III-V materials grown by molecular beam epitaxy (MBE) are extremely promising for photoconductive switches, which can be used as terahertz sources and detectors. This project, in close collaboration with PhD student Wilder Acuna, focuses on characterization of these materials (and devices made from them) to understand properties required for terahertz applications. Some specific techniques include Hall effect measurements for electrical characterization, high-resolution x-ray diffraction (HR-XRD) to determine epitaxial film quality, and atomic force microscopy (AFM) to analyze surface quality, as well as measurements in collaboration with other IRG research groups. The student will also learn about MBE, a technique that allows the growth of high quality single-crystal semiconductors with exquisite control, including the ultrahigh vacuum technology that enables it and the mechanisms to control material composition and morphology.

Faculty mentor: Prof. Stephanie Law (Research group)
Graduate mentor: Yongchen Liu

Topological insulators (TIs) are exotic materials that ideally can only carry current on their surfaces. These materials have a variety of applications including terahertz sensors, low-resistance wires, spintronics, and so on. In addition to their unusual electrical properties, they are also predicted to show unusual responses to applied magnetic fields. This project will focus on measuring the optical response of TI nanostructures when subject to an external magnetic field. From this data, we will learn significantly more about these exotic materials both at a fundamental level and with an eye toward applications. The student will learn how to use Fourier transform infrared spectroscopy, how to take transmission measurements, how to plot and analyze data, how to model data using existing programs, and how to work with other experimentalists and theorists to understand the data.

Faculty mentor: Prof. Lars Gundlach (Research group)
Graduate mentor: Joe Avenoso

Understanding the interaction between novel hybrid materials and THz radiation on time-scales as short as picoseconds is important for designing new and improving existing THz materials and devices. In this project the techniques and instrumentation necessary for measuring ultrafast THz response are applied, improved and developed. One focus of this project lies on implementing polarization-, temperature- and magnetic field-control in visible pump – THz probe spectroscopy. Students will work closely with the PhD student overseeing the project. They will be introduced to working with advanced ultrafast optical instrumentation and how to modify it for specific measurements. Students will learn how to conduct ultrafast time-resolved spectroscopic measurements, analyze the acquired data, and interpret the results..

Faculty mentor: Prof. Benjamin Jungfleisch (Research group)
Graduate mentor: Tomal Hossain

Antiferromagnetic spintronics and magnonics offer distinct advantages over their ferromagnetic counterparts since they are robust against charge and magnetic field perturbations. Antiferromagnets (AFMs) exhibit zero net magnetization and therefore lack stray fields, which enables high-density storage concepts. Synthetic AFMs and van der Waals (vdW) AFMs can serve as a model system for studying AFM ordering and magnon excitations. This project will focus on the characterization of synthetic AFMs and vdW AFMs by microwave spectroscopy and time-domain THz spectroscopy. In particular, the student will work on magnetic-field dependent THz emission in these systems providing the potential for realizing magnon-based hybrid systems. The student will learn how to conduct optical and microwave experiments, how to analyze and interpret the data, and how to model the experimental results.

Faculty mentor: Prof. John Xiao (Faculty profile)
Graduate mentor: Subhash Bhatt

The project is to fabricate magnetic heterostructures consisting of ferromagnetic or antiferromagnetic materials, and understand how to generate and control THz emission. We focus on (1) 2-dimensional (2D) quantum Dirac magnetic materials, whose properties are sensitively depending on interface and bias voltage, and (2) novel antiferromagnetic materials, which show spin-dependent transport properties similar to those of ferromagnetic materials (easy to control and easy to read out) while keeping the advantages of antiferromagnetic materials in orders of magnitude improvement in operation speed and much reduced energy consumption over ferromagnetic materials. The REU student will primarily work on developing 2D magnetic materials and heterostructures.

Faculty mentors: Prof. Anderson Janotti (UD) and Dr. Garnett Bryant (NIST) (Research group)
Graduate mentors: Dai Quoc Ho and Ruiqi Hu

The chemical composition and crystalline structure across interfaces play central roles in the response of complex hybrid materials to THz radiation. Band alignments, Schottky barrier heights, charge transfer, and formation of two-dimensional conducting channels at the various interfaces of interest, such as semiconductor/semimetal, semiconductor/topological-insulator, and semiconductor/magnetic-material, are examples of parameters and phenomena that strongly impact the ability of a given material structure to generate or detect THz radiation. First-principles calculations based on density functional theory is a powerful tool in the study of fundamental processes associated with surfaces and interfaces of materials, enabling access to quantities that are often difficult to determine experimentally but are fundamental to understanding the materials behavior. The student will be exposed to state-of-the-art methods in electronic structure theory and will have the opportunity to create/modify computer codes that will help in data processing and analysis of first-principles calculations.

Faculty mentors: Prof. Xi Wang (UD) with Prof. Thomas Searles (UIC) (Wang Research group)
Graduate mentor: Zhixiang Huang

This project aims to demonstrate dynamically tunable THz metamaterials, which manipulate the properties of incident THz light. The REU student will focus on numerical simulations to model several THz metamaterials. In addition, the REU student will work with the mentor to analyze collected experimental data.

Faculty mentor: Prof. Mark Ku (Research group)
Graduate mentor: Shahidul Asif

Due to their layered nature, two-dimensional (2D) materials provide a highly tunable family of materials for next generation devices. In particular, the recently discovered 2D magnetic materials have the potential to serve as a versatile platform for the generation, manipulation, and detection of THz signals. Towards this end, fundamental understanding of their properties is necessary, which require highly sensitive probes. This project will focus on the study and characterization of 2D magnets based on quantum sensors realized with nitrogen vacancy centers in diamond. The student will work on constructing parts for quantum sensing setup, operating the setup to measure 2D magnets, and analyzing data. The student will learn how to work with opto/mechanical/electronic components of an experimental setup, conducting quantum science experiments, and interpreting results.