(4if) Nature-Inspired Smart Soft Materials for Agricultural Applications

Motivation and future research:

With global population projected to be over 9 billion by 2050, there is a pressing need to produce more food and utilize existing water resources with higher efficiency. However, traditional agricultural irrigation techniques including flood irrigation, and sprinkler irrigation, often utilize large amounts of water and result in significant water wastage. Additionally, in developing countries, limited access to and high costs associated with soil sensors and plant wearable monitoring devices significantly impede the optimization of plant growth efficiency. Therefore, innovative agricultural practices with advanced materials and affordable, user-friendly monitoring devices are needed to maximize water use efficiency and enhance plant growth.

Soft materials like hydrogels and smart ionic gels are gaining attention for their benefits in improving plant growth efficiency, including water retention, nutrient transport, precise nutrient management, and responsiveness to stimuli. In addition, biopolymeric soft materials are biocompatible and non-toxic for safe use in plant wearables. Developing nature-inspired soft smart materials by incorporating either artificial photonic crystals or aligned nanofibers can help cater to a broad spectrum of agricultural applications. By incorporating photonic crystals into soft materials, we enable color-based visual monitoring of soil/plant conditions such as humidity, pH, temperature, and nutrient levels, eliminating the need for electricity and complex circuitry. By incorporating aligned nanofibers into soft materials, we facilitate spatially controlled water and nutrient flow into plant roots and xylem tubes. Furthermore, composites with aligned fibers can serve as artificial roots, efficiently directing water and nutrient flow to plants and reducing water wastage.

My lab will develop various nature-inspired biopolymeric soft materials having varied morphologies and hierarchical structures to particularly tackle agricultural challenges. Specifically, my lab will develop visual soil/plant monitoring devices as well as artificial water and nutrient delivery systems for efficient plant growth by reducing water wastage. Below are brief overviews of areas of interest for my lab:

Area 1: Combining additive manufacturing and electrospinning for preparation of artificial plant roots and water delivery implants

Plant growth can be controlled and enhanced by directing the water and nutrients in the plant systems (e.g. xylem tubes and roots). Incorporation of aligned nanofibers into plants can allow tunability of the directional flow and enhance their growth even in harsh environmental conditions. For this, aligned biopolymeric nanofibers will be fabricated using electrospinning techniques and then subsequently incorporated into three dimensional (3D) printed biocompatible polymers having varied geometries. Then, these composites will be incorporated into plant systems for further solvent and nutrient diffusion and transport studies.

Area 2: Biofriendly polymers containing opal structures for monitoring humidity, nutrients, temperature and pH

Biofriendly polymers containing opal structures offer several advantages, including visual color changes in response to stimuli without the need for electrical components, and they are often biocompatible and biodegradable. pH and temperature monitoring systems containing opal structures will be prepared using three-dimensional (3D) printing to monitor the environment surrounding plant systems.

Previous and current research:

Previous research-

For my PhD, I worked in the Nanobiofabrication lab under the guidance of Prof. Hyunmin Yi at Tufts University. My dissertation work was on micromolding-based fabrication of responsive soft material platforms (e.g. films and microparticles) having tunable micropatterned opal structures. I developed various soft materials, including synthetic and biopolymeric hydrogels, as well as eutectogels containing opal micropatterns, in multiple formats such as films and microparticles. These soft material platforms containing opal micropatterns showed reversible responsiveness towards pH, ionic strength, water content, electrical stimuli, and temperature readily manifested via large shifts in color. Combined, the micromolding based technique resulted in controlled fabrication of multiformat responsive soft materials with a broad range of functionalities and applications. In addition to my individual research duties, I was fortunate to mentor 14 graduate and undergraduate students during my time as a PhD student.

My scholarly contributions include: 1. ACS Appl. Eng. Mater., 1(8), 2217-2227 (https://pubs.acs.org/doi/10.1021/acsaenm.3c00293), 2. ACS Appl. Mater. Interfaces 2022, 14, 51, 57481–57491 (https://pubs.acs.org/doi/full/10.1021/acsami.2c20266), 3. Langmuir 2021, 37, 4, 1456–1464 (https://pubs.acs.org/doi/10.1021/acs.langmuir.0c02983), and 4. Yi, H., Bukenya, M., & Kalidindi, S. (2024). U.S. Patent Application No. 18/271,135.

For my master’s thesis work at The University of Toledo under the guidance of Prof. Ana C. Alba-Rubio, I worked on synthesis of 5-hydroxymethylfurfural (HMF) from glucose and fructose using reusable polymer catalysts. My MS thesis work was recognized with outstanding thesis award by the School of Engineering at University of Toledo. This work resulted in a patent (https://patents.google.com/patent/US20200360910A1/en) and co-first author publication in the Catalysis Science & Technology journal (Catal. Sci. Technol., 2023, 13, 132-146; https://pubs.rsc.org/en/content/articlehtml/2022/cy/d2cy01619b). I had helped Prof. Alba-Rubio set up the lab from scratch, being her first graduate student at UToledo.

For my bachelor’s thesis work, I worked on extraction of phenols from coal tar oil using binary solvents and ionic liquid mixture. This work resulted in publication (Int. J. Oil, Gas and Coal Technology, Vol. 23, No. 2, 240–260; https://doi.org/10.1504/IJOGCT.2020.105454)

Current research-

I am currently a postdoctoral researcher in the Korley Research Group (KRG) at the University of Delaware (UD) working under the guidance of Distinguisher Professor LaShanda T.J. Korley. My research focus is on 1. fabrication of responsive composite materials containing aligned nanofibers using electrospinning technique, and 2. additive manufacturing to prepare nature-inspired responsive materials having varied morphology and hierarchical structures. In addition to performing my independent research, I mentor multiple graduate and undergraduate students in the KRG group.

Teaching Interests

Based on my previous teaching experience, I have a strong command of the following courses among other core chemical engineering courses:" 1. Graduate and Undergraduate level Transport Phenomena, 2. Heat and Mass Transfer, and 3. Catalysis and Reaction Engineering. If I were given an opportunity as an assistant professor, I would like to design a specialized course on biomaterials and their applications in biosensing and drug delivery. The course material would cover - 1. Introduction to natural biomaterials, 2. Fundamentals of biopolymeric hydrogels and resins and 3. Applications of biomaterials including but not limited to point-of-care and drug delivery.

Teaching Experience:

1. Graduate Teaching Assistant at Tufts University:

I was a graduate teaching assistant (TA) during my PhD journey at Tufts University from January 2018 to September 2021. During this time, I was the TA for the following courses:

1.1. Undergraduate Courses:

1. CHBE 102 - Reactor Design (Spring 2018), Professor in-charge of course: Prof. Kyongbum Lee

1.2. Graduate level Courses:

1. CHBE 204 - Advanced Transport Phenomena (Spring 2019), Professor in-charge: Prof. Prashant Deshlahra

2. CHBE 168 - Biotechnology Processing Projects Laboratory (Fall 2019 and Fall 2020), Professor in-charge: Prof. Hyunmin Yi

2. Graduate Teaching Assistant at the University of Toledo:

I was awarded a full scholarship (complete tuition waiver and stipend) at the University of Toledo (UToledo) for the entirety of my master’s degree. The Scholarship required me to be a graduate teaching assistant for at least three semesters. While at UToledo, I was the TA for the following courses:

2.1. Undergraduate Courses:

1. CHEE 2010 - Material and Energy Balance (Spring 2016), Professor in-charge: Prof. Matthew W. Liberatore

2. CHEE 3400 - Process Dynamics and Control (Fall 2016), Lecturer in-charge: Mr. Bradley Yaniga

3. CHEE 3110:001 - Process Heat Transfer (Spring 2017). Professor in-charge: Prof. Maria R. Coleman