Flexible and implantable electronics

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Due to the superior mechanical property and high electronics bandgap of SiC, we discovered that this material is a promising building block for biological applications such as a versatile platform for cell growth and stimulation. Relevant to the proposed project, we demonstrated ultra-thin SiC membranes for cell culture and stimulations (ACS Appl. Mater. Interfaces, 9 (48), 41641-41647), and developed a novel integrated microfluidic SiC devices with heating and cooling capability as well as sensing (Adv. Mater. Interfaces 5, 1800764). As the key researcher, we recently developed silicon carbide (SiC) nano-thin films as lasting wide bandgap bioelectrodes and biosensors for implantable applications. This pioneering work was published in the prestigious journal Proceedings of the National Academy of Sciences of the United States of America (PNAS 2022, 119(33): p. e2203287119). SiC is a promising material for wearable and implantable devices due to its biocompatibility, multimodality and robustness in highly corrosive environments. Furthermore, we also demonstrated hybrid SiC electrodes for sensing and intervention as an integrated endoscopy tool (published in ACS Nano 2022, 16(7): p.10890). This feature results from the significant sensing effects and transparency of SiC nano-thin films on an insulator.

MEMS micro/nano electronics for advanced sensing 

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We have successfully designed and developed fabrication techniques for SiC-based multi-variable microsensors for a broad range of applications by addressing several challenges in design, fabrication and testing of SiC for sensing applications under harsh conditions. The results were published in top journals of the field such as Elec. Dev. Lett., Appl. Phys. Lett., and J. Mater. Chem. C. In micro/nano fabrication, we innovatively utilised a direct ablation technique to fabricate SiC microstructures using a femto-second laser without the need for conventional cleanroom processes such as lithography and etching. This technique opens up opportunities for the rapid design and prototyping of SiC microelectronic devices (published in Adv. Eng. Mater. 22 (4), 1901173). Our fundamental discovery of the isotropic piezoresistance in SiC provided guidance for the design and optimisation for SiC based physical sensing devices (Appl Phys. Lett., 113 (1), 012104). 

Unusual material characterisations 

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We develop SiC sensing devices working under harsh conditions such as extremely high temperatures, and/or corrosive environments. We introduced an in-situ measurement method to characterise SiC strain and thermal sensors at up to 600°C (published in J. Mater. Chem. C 6 (32), 8613-8617) using a custom-built chamber with controlled high temperature, which can meet the elevated temperature requirements for most harsh conditions. The extended test regime allowed for the understanding of SiC devices towards unusual operation scenarios such as sensors for deep space explorations, extreme processing with high temperature and/or high pressure. We innovated the fabrication and characterisation of ultrathin free-standing SiC membranes, with an exceptionally large aspect ratio of 20,000, allowing for lab-on-chip biological applications such as cell culture and lysis (published in ACS Appl. Mater. and Interfaces 9(48): p. 41641-41647).

Micro actuator systems

We developed at ITIMS a novel MEMS electrostatic actuator that could generate driving forces substantially higher than its counterparts using alternating current (Microsyst. Technol., 21 (11), 2469-2474). We successfully solved the heat dissipation problem of thermal actuation and enhance the frequency response of the actuator. Additionally, we conceptualised and demonstrated miniaturised mechanical systems such as micro cam driven motors, and micro conveyor systems (Microsyst. Technol. 21 (3), 699-706). Our innovative micro systems provide not only proof of concept but also design guides for MEMS engineers.