The Tian group is dedicated to an integrative view of sciences, taking inspiration from a variety of fields, including physical chemistry, materials science, cell biology, biophysics, medical sciences and multiple engineering disciplines. The Tian group is interested in probing the molecular-nano interface between biological and semiconductor systems, placing an emphasis on novel material synthesis and device concept. This interest is focused around three goals:
- Synthetic Cellular Interactions:
- Nanoelectronic Exploration of Cellular Systems:
- Development of Biomimetic Nanoscale Materials and Devices:
P.I.N. Coaxial nanowires for energy conversion
Our group is interested in both imitating cellular behavior using semiconductor nanomaterials and the augmentation of existing biological systems with semiconductor components. We hope to stably incorporate inorganic materials into the pre-existing cellular frameworks, examining both how single cells interact with these new artificial components, and what uniquely inorganic properties (e.g., electrical and optoelectronic responses, bioorthogonality) we can exploit to derive a more nuanced control over these cellular systems. There are several motivations for wanting to pursue this type of research.
It has been shown that the extracellular environment can have a significant impact on cell morphogenesis and on the initiation of cellular signaling processes. We hope that by incorporating semiconductor nanomaterials into this environment we can use the physical properties of these materials to influence cell morphogenesis and motility. We hope that by augmenting these biological systems we can more carefully characterize these extracellular interactions and demonstrate a refined control over these environments.
Additionally, we are interested in examining how cellular systems will adapt to nonliving semiconductor nanomaterials, both intra- and extracellularly. Cells communicate via a variety of methods, including biochemical and biophysical signaling. We hope to either artificially mimic or assist in these types of cellular behavior by incorporating semiconductor frameworks, elucidating these forms of cellular responses. Recognizing how cells incorporate or exclude these types of semiconductor frameworks will help us further understand the fundamental limits in the biophysical signal transductions between biological and synthetic systems, and could lead to innovative therapeutic pathways.
100nm Diameter Kinked Nanowire FET
The ability to monitor the electrophysiology of living cells in real time with good spatiotemporal resolution is crucial for advancing our knowledge of cellular signaling pathways. However, minimally invasive intracellular or intercellular recordings, have been difficult to obtain as traditional techniques use probes that are too large to leave the cell membrane intact or to allow for satisfactory spatiotemporal resolution. Similarly, the rigidity of many of these devices prevents them from easily interfacing with flexible biological systems. Our group is interested in developing original solutions to overcome these obstacles, allowing for improved intracellular or intercellular recordings.
Nanostructured field effect transistors are uniquely positioned to explore the electronic properties of cellular systems as they offer a platform that is small enough to both, probe specific cellular interactions and to cause minimal disturbances to the cell's membranes and organelles. Additionally, nanostructured transistors have demonstrated good signal to noise ratios as compared to other similarly sized recording systems, leading to improved data acquisition. This offers the opportunity for novel cellular measurements, illuminating the electrical properties of biological materials.
Nanoelectronics scaffold for wiring synthetic tissue.
Nature routinely uses proteins to design complex three dimensional structures at nanometer scales with great precision. While traditional organic synthesis methods have yielded excellent specificity in chemical products, these are typically limited to molecular length scales and the difficulty of synthesizing these products increases exponentially with size and functional composition. However, as inorganic nanomaterial synthesis methods improve, scientists and engineers are able to utilize these techniques for designing novel nanoscale systems of length scales comparable to natural systems, allowing for unique interactions.
Additionally, biological systems are capable of a large degree of morphological and synthetic control, achieving these transformations under relatively benign conditions (in aqueous solutions, at room temperature and without cytotoxic reagents). We are interested in probing these types of systems, utilizing naturally inspired processes for semiconductor material synthesis. Finally, biological systems exhibit many unique properties not commonly observed in semiconductor materials such as homeostatic regulation and environmental adaptability. We are interested in exploring analogs to these types of behaviors in semiconductor systems, examining how these insights can be applied towards new material and device designs, with applications in regenerative medicine and renewable energy.
To achieve these goals will require new synthetic approaches and device concepts, producing nanoscale semiconductor materials and devices which are both biocompatible and exhibit desirable physical properties. By examining these processes we hope to gain a deeper insight into biological-semiconductor interfaces, pushing the limits of what is considered possible!