Bioelectrical and Life-like Interfaces
Biological systems respond to and communicate through biophysical cues, such as electrical, thermal, mechanical and topographical signals. The mission of the Tian lab is to discover new bioelectrical signaling processes in cells and tissues and, to that end, establish a new paradigm for bioelectronic medicine.
We are a team of exploration- and curiosity-driven scientists. We employ advanced material tools to introduce localized physical stimuli and/or sense biological responses to biophysical signals with high spatiotemporal resolution. In working towards a new paradigm in bioelectronic medicine, we have employed a range of material synthesis and device design principles, revealed multiple signal transduction mechanisms at bioelectronic and biophotonic interfaces, and pushed the limits in organelle level biointerfaces.
In particular, we present a new concept in minimally invasive biological modulation: a non-genetic approach that offers the flexibility of optical stimulation. In many of our studies, we chose biocompatible semiconductors, such as silicon or silicon carbide nanostructures, which can target a single cell or subcellular component.
Parallel to our studies of biological modulations, we have recently developed a range of synthetic materials that display tissue-like mechanics. The goal of this new line of research is to identify key biomaterial parameters that will improve signal transduction in future biomedical implants and medical robotic devices.
Biological tissues are highly complex electrochemical computing machines with many components and interconnections. The architecture, sensing mechanisms, inter-component communication and computing protocols of biological tissues are only starting to be deciphered on the scale of small circuits in a rudimentary manner. To advance our understanding of bioelectrical complexity, we need new tools and biomaterials that can interrogate bioelectrical and biomechanical activities or establish seamless biointerfaces at different length scales.
Soft and hard materials exhibit mismatched behaviours, such as those in chemical or biochemical reactivity, mechanical response and environmental adaptability. Exploration of interfacial mismatches and their associated chemical processes may reveal numerous opportunities in both fundamental studies and applications.
We have identified and quantified the physicochemical outputs from the photo-thermal, -faradic, and -capacitive effects of nanostructured semiconductors at biointerfaces. We have demonstrated how these physicochemical outputs can be utilized at semiconductor-based biointerfaces to modulate electrical activities in neurons, cardiomyocytes and bacterial cells
Tissues such as human skin are multicomponent and hierarchical, mechanically heterogeneous and anisotropic, self-healing, impact-absorbing, and dynamically responsive. Traditional synthetic materials, on the other hand, do not typically possess such multiscale and dynamic responsiveness. We are exploring synthetic tissue-like materials for bioelectronics and robotics applications.