Research Interests

Aerial view of the Virginia Tech campus in Blacksburg, Virginia.

Our research aims at improving the health, productivity, and well-being of animals by introducing structural innovations guided by recent developments in microelectromechanical systems (MEMS), advanced manufacturing, and wearable technology. The overarching objective of our research is to identify a set of biomarkers associated with diseases and agriculture parameters with advanced biosensors. Livestock diseases caused by pathogenic microorganisms (bacteria, viruses) or stressors threaten the health and well-being of livestock, limit productivity, and increase economic losses. We thus expect to address the unmet need for farm-side monitoring systems to improve livestock health and welfare. Further, biosensors combined with wearable technology enable the monitoring of physiological biomarkers, stress, virus/bacterial infection, and infectious diseases.

The use of biosensors combined with the Internet-of-Things will bring animal health and welfare management to the next level of precision livestock farming. To realize this goal, we are exploring 3D printing and micro/nanofabrication tools to build next-generation sensors for real-time measurements of biomarkers to support precision farming. These sensing tools not only help farmers make decisions but also help people with personalized medicine. We are exploring various sensing modalities, including impedimetric spectroscopy, voltammetric, Chrono and capacitive, field-effect transistor, plasmonic, photonic crystal, and fluorescence to make the sensor devices. Our lab utilizes numerous smart materials, including nanomaterials (1D, 2D, and 3D), microelectrode arrays, conducting polymers, biomimetic materials, etc., with their unique functional properties and surface chemistries to construct the sensor parts. Small electronic circuits will be embedded to collect the readout signals. The ultimate goal of our research is to develop portable and affordable sensors that farmers can operate for real applications. Current research areas are covered below.

Photo above: A high-resolution scanning electron microscope (SEM) image reveals a dense array of vertically aligned, hollow micropillars with porous, textured surfaces. Fabricated via high-precision 3D printing, these uniform cylindrical structures are arranged in a grid and feature central hollow cores and rough outer walls—designed to maximize surface area for biomolecule immobilization.

These micropillar arrays function as high-performance 3D electrodes. Their elevated surface-to-volume ratio significantly enhances electron transfer and sensitivity, making them ideal for detecting ultra-low concentrations of analytes such as proteins, nucleic acids, or small molecules. This nanostructured platform offers powerful capabilities for electrochemical sensing in clinical diagnostics, environmental monitoring, and point-of-care testing. Adapted from Ali et al., Adv. Funct. Mater. 2022, 32, 2107671.

3D Biosensors

3D manufacturing with nanostructure allows complex sensing geometries with multifunctional materials to enhance device functionality. Nano-interfaces enabled with 3D surfaces can enhance the devices’ figures of merit. In addition, low-cost, rapid prototyping and customization are the main desirable features of 3D printing to develop a new class of 3D biosensors. We aim to develop unique sensing characteristics by using additive manufacturing techniques to create next-generation biosensors for monitoring the health of livestock animals and humans.

Lab-on-a-Chip and Microfluidic Devices

These integrated miniaturized platforms can perform single or multiple laboratory functions at the same time on a small scale. With these functionalities, microfluidic devices can be easily interfaced with wearable electronics and detection systems for the rapid detection of biomolecular events. We are exploring a set of lithographic methods to build lab-on-a-chip devices integrated with microfluidics and MEMS-based microelectrode array, to perform manipulation of minute amounts of biofluids (sample pre-processing) and detection of biomarkers (antibodies, proteins, metabolites, cell receptors, etc.) at the same time. Further, these devices allow for the testing of multiple targets (multiplexing) at or near a farm-side. Thus, these devices will be useful for farmers and veterinarians.

All-Solid-State Sensors

These sensors are useful for many real applications, as they are portable, liquid junction free, small, calibration-free, and user-friendly. We aim to develop low-cost and affordable all-solid-state sensors for deploying on livestock herds and measuring signals continuously. Unlike traditional bulky sensors, the ion-to-electron transducers allow miniaturization and long-term deployability. These sensors not only serve as continuous monitoring systems to improve animal/crop health but can also support climate-smart agriculture.

Wearable, Flexible, and Implantable Biosensors

We aim to develop wearable and flexible printed sensors for animal sensing. These sensors can be embedded in animal bodies or mounted on animal skins to perform real-time measurements of physiological information, drugs, and markers due to diseases, stress, and virus or bacterial infection. Combined with portable electronic circuits, the miniaturized and fully integrated devices will be useful for farmers to enhance the biosecurity of animal herds and promote decision-making. The ultimate goal of our research is to develop monitoring detection systems that are useful for real applications in farming fields.

See our publications

Schematic of a nanomaterial-based biosensor illustrating both 2D and 3D elements, with biorecognition molecules capturing target analytes on a 3D nanostructured transducer surface, and dynamic arrows indicating signal transduction and detection pathways. — In this photo, the device shown was developed to break a fundamental barrier in medical diagnostics—detecting ultra-low concentrations of critical biomolecules. Using 3D aerosol jet nanoprinting, engineers created a micropillar electrode system capable of detecting dopamine at femtomolar levels—equivalent to a few molecules in a vast volume. This is a major advancement because dopamine is a key neurotransmitter involved in mood regulation, motor control, and neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and schizophrenia. Its presence in blood is extremely low, making detection technically difficult. By shifting from flat 2D surfaces to high-surface-area 3D microstructures coated with graphene nanoflakes, the sensor traps more molecules as fluid flows through a microchannel, vastly improving sensitivity. This allows minimally invasive blood tests to screen for neurological disease biomarkers earlier than ever before—paving the way for faster diagnosis, better monitoring, and timely interventions. Adapted from Ali et al., Nature Communications, 12(1),7077, 2021

Schematic of an integrated electrochemical biosensor system combining microfluidics, nanostructured transducers, and wireless data transmission, shown at approximately the size of a U.S. quarter to highlight its compact, portable design for point-of-care diagnostics. — Shown next to a U.S. quarter for scale, this compact lab-on-a-chip biosensor features a transparent microfluidic chip with 3D-nanoprinted microelectrode arrays coated in reduced graphene oxide and functionalized with SARS-CoV-2 antigens. Fluidic tubing delivers samples to the electrodes, while three color-coded wires (red, white, black) transmit real-time impedance signals—secured by a green patterned adhesive. Within 10 seconds, antibody binding alters impedance detected via impedance spectroscopy, enabling femtomolar sensitivity, with results displayed on a smartphone. The sensor regenerates in under one minute using a low-pH buffer, shows no cross-reactivity, and can be adapted for other pathogens such as HIV, Ebola, and Zika. Photo courtesy of Azahar Ali.