We are an interdisciplinary experimental group that is developing microbiorobotics, nano/microfluidics, and nanopore technologies for biological applications.
ongoing research program can be broadly categorized into three core subject areas: micro/nanorobotics, single cell/single molecule biophysics, and transport phenomena. Although each core program consists of a distinct project, we would like to emphasize their synergistic nature – advances in one core are expected to drive the development of the others. The unifying component of all the cores is “biologically inspired nano/micro engineering.”
Rapid advances in science and engineering over the past 20 years have enabled us to manipulate matter down to the atomic level. With this unprecedented level of control over matter extraordinary new technologies are being developed with applications spanning a diverse array of fields ranging from biology to robotics. Today there exist a diversity range of nano/microfabrication techniques that are capable of producing small scale functional materials and devices. These new stimuli responsive devices open up the possibility to probe biology on the length scales where fundamental biological processes take place, such as epigenetic and genetic control of single cells. Currently our lab is actively researching four broad topics revolving around small scale engineering: Microbiorobotics for Manipulation and Sensing, Synthetic Nanopore Fabrication and Single Molecule/Single Cell Analysis, Biologically Inspired Metamaterials for Nano/Optoelectronics, and Swimming and Flying at Low Reynold Number.
We are always happy to work with motivated students who have a passion for research. If you are interested in joining our lab, it is recommended that you kindly email Professor MinJun Kim to talk about your qualification and research interest as early as possible.
Research Thrust #1: Microbiorobotics for Manipulation and Sensing
Microrobotics offer the possibilities for many applications including in micromanipulation and microfabrication, drug delivery, and minimally invasive surgery. To overcome challenges of low Reynolds number dynamics in viscous and viscoelastic fluids, BAST lab works at the interface between microbiology and robotics to create three categories of nature inspired microrobots: the achiral microswimmers, the bacterial-powered hybrid microbiorobots, and magnetotactic cellular microrobots. These microscale robots had demonstrated low Reynolds number navigation, microscale assembly, and automatous control.
The magnetically actuated achiral microswimmer consists of 3-beads rigidly linked using biotin-avidin chemistry. This swimmer is capable of converting rotating motion into translational motion in bulk fluid at low Reynolds number without the commonly regarded conditions of flexibility or chiral geometry. The achiral swimmers are actuated wirelessly using an external rotating magnetic field supplied by approximate Helmholtz coils. The achiral microswimmers exhibited active propulsion and were controllable in both speed and direction. We are currently working on multiple robot control to manipulate a team of microswimmers as a viable workforce and modular microrobotics for dynamic adaptability to heterogeneity environments.
Flagellated bacteria are integrated with engineered systems to construct bacterial-powered hybrid microbiorobots (MBRs). MBRs are microfabricated SU-8 epoxy structures with typical feature sizes ranging from 5 – 100 microns coated with a monolayer of the swarming Serratia marcescens, where the adherent bacterial cells naturally coordinate to propel the microstructures in fluidic environments. We explore some design aspects, such as the effects of bacterial density, distribution and orientation on the surface of the MBRs, as well as various modalities to control the bacteria. A number of different stimuli, including ultraviolet light, electric field, chemotactic gradient, and thermal stimuli are used as control inputs to manipulate the MBRs into performing sample tasks since as cargo transport and microassembly.
The magnetotactic cellular microrobot fuses micro-scale inorganic components with cellular actuators for object manipulation which is a great challenge in micro-scale robotics (length scale of 1 micron to 1 mm). Specifically, we are fusing inorganic actuators onto live microbial cells so as to use them as micro-scale robots, essentially creating what we call “micro-cyborgs”. Our approach in fusing inorganic actuators and biological actuators constitutes a novel direction in microbiorobotics. Currently, researchers have explored separate use of bio-inspired engineered structures (such as artificial flagella) and live cells (such as bacterial swimmers) as micro-scale actuators. In this research, we seek to combine the merits of both types of actuators, e.g. repeatability and specificity of inorganic actuators and low cost of biological actuators. The biological part of our micro-cyborg is an artificially magnetotactic Tetrahymena pyriformis. Joint use of multiple micro-cyborgs can result in manipulation of larger objects. The range of operation of micro-cyborgs makes them potentially useful in biomedical applications (e.g. cell manipulation) and micro-assembly.
Research Thrust #2: Synthetic Nanopore Fabrication and Single Molecule Analysis
Research Thrust #3: Biologically Inspired Metamaterials for Nano/Optoelectronics
Research Thrust #4: Swimming at Low Reynolds Number: Many microorganisms swim
Flapping Wing Flight: By thoroughly studying the aerodynamics of beetle flight, it is possible to bleach the limitations in developing micro/nano aerial vehicles, specifically the difficulties to fabricate an assortment of machinery parts and and developing miniaturized power sources. Our research is focused on characterizing the flapping wing kinematics and aerodynamics of beetles. Key interest lies in the beetles’ ability for non-jumping take-off and hovering flight. The final goal of this research is to develop beetle cyborgs with the extraordinary flight characteristics of the beetles.
Past Research Projects
– Fabrication of Single-digit Nanometer Solid-state Pore for Single Molecule Analysis
– Bacterial Flows: Mixing and Pumping in Microfluidic Systems Using Flagellated Bacteria
– Microfluidic Flow Control Using Electroosmosis