Micro/nano system modelling and manipulation


Nanotechnology is playing a key role in fields such as materials, microbiology, nanomedicine, nanorobotics and the environment. Recent advances have translated into widespread opportunities to investigate and manipulate materials at nanoscale. Here at IISRI, we're getting right down to the fine details of this exciting technology.


The big effect of nanotechnology

At IISRI we're well aware of the number of revolutionary nanotechnologies that have emerged over recent decades. But, despite their potential, many of these tools are not without their shortcomings. We dedicate our time to eliminating these weak spots and accelerating this field of research.

Our projects have far-reaching effects, from manufacturing to defence training and the health industries. Microsurgery and medical research are particularly suitable areas to feel the benefits of advancements in micro/nano technologies.


Researchers get their hands on the nano-world

Current advancements in nanotechnology are dependent on the capabilities that enable nano-scientists to extend their eyes and hands into the nano-world. For this purpose, we are proposing a haptics-based system for an AFM (atomic force microscope). The system enables nano-scientists to touch and feel sample surfaces viewed through an AFM, to better understand the physical properties of the surface and the shape of the molecular architecture.

Featured researcher

Alfred Deakin Professor Ian (Ying) Chen is renowned internationally for his work in nanomaterials and nanotechnology. So much so, he and his team recently secured Deakin a $1 million grant under the Australian Research Councils Linkage Infrastructure, Equipment and Facilities (LIEF) scheme to contribute to the purchase of a state-of-the art Field Emission Gun Transmission Electron Microscope.

Deakin led the grant application and my name is attached to that, but it could not have happened without the really genuine support of a team of people, both at Deakin and from other universities and research bodies. When you get that sort of support from your own university, it says to the outside world that you are really serious about this research area.

Professor Ian Chen

ALFRED DEAKIN PROFESSOR

Research projects

Force feedback-enabled minimally invasive surgery/microsurgery system

The parallel robot-assisted, force feedback-enabled, minimally invasive surgery/microsurgery system (PRAMiSS) is composed of a 6-RRCRR parallel micromanipulator and a linear guide (monocarrier) carrying an actuated force feedback-enabled laparoscopic instrument. 

The manipulator and the monocarrier are connected through a closed chain RPRR mechanism, whose last revolute joint is actuated (R) and is able to change the angle of the monocarrier and the instrument attached to it. The actuated monocarrier also makes it possible to insert or withdraw the instrument in the direction that it points. The RPRR mechanism is fixed to the moving platform of the parallel micromanipulator. The moving platform is connected to the base by six extendable RRCRR legs that enable it to have six translational and rotational DOFs.

The motion control architectures proposed for this system enable it to achieve milli/micro manipulations under the constraint of moving through a fixed penetration point without any mechanical constraint. Control algorithms also apply orientation constraints.

Automated force feedback-enabled surgery instrument

We have developed a force feedback-enabled, minimally invasive surgery instrument that is able to measure tip/tissue lateral interaction forces, as well as normal grasping forces. This supports a sense of touch in robotically-assisted, minimally invasive surgery operations, enabling the characterisation of soft tissue of varying strength. 

The instrument can also adjust grasping direction and change tip types (e.g. cutter, grasper, and dissector) as needed. In order to measure the tip/tissue lateral and normal interaction forces, strain gauges were incorporated into the instrument tube and the actuation and transmission module.

Dynamic nanofin heat sinks

This research developed nanotechnology-enabled heat sinks that can be magnetophoretically formed onto the hot spots within a microfluidic environment. CrO2 nanoparticles, which are dynamically chained and docked onto the hot spots, establish tuneable high-aspect-ratio nanofins for the heat exchange between these hot spots and the liquid coolant.

Neural microelectrodes on microfluidics: interfacing nerve cells on an integrated microfluidics platform with electronics and software systems

Cultured neuronal networks (nerve cells cultured in vitro inside microelectrodes arrays) have been used in 'rat-brained robots' – robots driven, not with digital microcontrollers, but with nerve cells. Microfluidics (lab on a chip) platforms have emerging applications that could replace clinical trials e.g. 'lung on a chip', 'heart on a chip' or 'organ on a chip'.

In brain and neuroscience research, and in vivo body electronics implant industries, flexible, easy to microfabricate microelectrodes are also researched to find replacements for metal electrodes. This research will focus on the development of an integrated platform of those promising technologies into a modular platform, interfacing nerve cells cultured in immobilised microstructures inside microfluidics with embedded systems, and investigation of dynamics of bi-directional communication between neuron and silicon.

In vitro and microfluidic nerve networks can be stimulated, the firing of neurons can be recorded, and patterns can be analysed with a data acquisition and control embedded system. Such an integrated platform can be useful to:

  • research robotics applications 
  • replace clinical trials 
  • become a part of personal, preventive self-diagnostic instruments (so that medical care costs can be reduced) 
  • make better and cheaper in vivo bio-electronics implants 
  • make biosensors and bioMEMS.

At a glance – cellular biology for engineers

There's a growing demand for engineers to expand their roles into cellular biology research. However, the stumbling block is how to impart the information in the cellular biology literature to an engineering audience. 

This research aims to overcome this bottleneck by describing the human cell components as micro-plants that form cells as micro-bio-factories. This concept can accelerate the engineers' comprehension of the subject. Complex interactions are translated into simple flow diagrams, generally used by engineers to represent multi-component processes.

Dielectrophoretic manipulation and separation of microparticles using curved microelectrodes

This research investigates the development and experimental analysis of a dielectrophoresis (DEP) system, which is used for the manipulation and separation of microparticles in liquid flow. The system is composed of microelectrodes integrated to a microchannel. Novel curved microelectrodes are symmetrically placed, with respect to the centre of the microchannel, with a minimum gap of 40 μm. The computational fluid dynamics method is used to characterise the DEP field and predict the dynamics of particles. 

The performance of the system is assessed with microspheres of 1, 5 and 12 μm diameters. When a high-frequency potential is applied to microelectrodes, a spatially varying electric field is induced in the microchannel, which creates the DEP force. Negative-DEP behaviour is observed with particles being repelled from the microelectrodes. 

The particles of different dimensions experience different DEP forces and settle to separate equilibrium zones across the microchannel. Experiments demonstrate the capability of the system as a field flow fraction tool for sorting microparticles according to their dimensions and dielectric properties.

Size-based separation of microparticles using a dielectrophoretic-activated system

This research investigates the separation of polystyrene microparticles suspended in deionized (DI) water according to their dimensions using a dielectrophoretic (DEP) system. The DEP system utilises curved microelectrodes integrated into a microfluidic system. 

Microparticles of 1, 6, and 15 μm are applied to the system and their response to the DEP field is studied at frequencies of 100, 200 and 20 MHz. The microelectrodes act as a DEP barrier for 15 µm particles and retain them at all frequencies, whereas the response of 1 and 6 μm particles depends strongly on the applied frequency. 

 At 100 kHz, both particles are trapped by the microelectrodes. However, at 200 kHz, the 1 μm particles are trapped by the microelectrodes while the 6 μm particles are pushed toward the sidewalls. Finally, at 20 MHz, both particles are pushed toward the sidewalls. The experiments show the tunable performance of the system to sort the microparticles of various dimensions in microfluidic systems.