The core of our research is to innovate scalable nanotechnologies to address grand challenges facing our society.

From the Stone Age to the silicon chip, advancing materials and tools has been the foundation throughout human evolution.  In our research group, we are interested in developing new materials and electronic tools to tackle grand societal challenges in health, environment and energy.  Our research program currently consists of the following three synergistic thrusts: 1) Sensors; 2) Modulation & Actuating Devices; 3) Electro-Catalysts. Our interests span from fundamental materials science, to emerging device concepts, to ubiquitous electronic systems.


1. Sensors

1.a. Bio-sensing. In this theme, we aim to build next generation electronic and optoelectronic tools and biomedical devices for various applications, such as brain activity mapping, diagnosis and treatment of neurological disorders and heart diseases, and neuro-prosthesis.  Specifically, our research efforts will be focused on: i) very-large-scale integration of nano-electronic and nano-photonic devices and ii) novel nanoscale devices for brain recording, with a long-term goal towards wireless communication.  We are also interested in non-invasive biomedical sensors for personal health informatics. 


Recent papers:
1). ACS Nano, 11, 4365–4372, 2017.
2). Nature Biomedical Engineering, 1, 0038, 2017.
3). Proceedings of the National Academy of Sciences (PNAS), 113, 11682-11687, 2016.

1.b. Chemical sensing. In this theme, we aim to leverage scalable atomic semiconductors to develop  miniaturized, ultra-sensitive and selective chemical sensing devices.  Over the past several years, we have been pioneering the materials processing and fundamental studies of semiconducting atomic layers, ranging from ultrathin III-V compounds, to 2-dimensional transition metal chalcogenides, to ultrathin Si. 


Recent papes:
1). Proceedings of the National Academy of Sciences (PNAS), 114(28), E5522-E5529, 2017.
2). Proceedings of the National Academy of Sciences (PNAS), 111 (17), 6198-6202, 2014.
3). Proceedings of the National Academy of Sciences (PNAS), 110, 11688-11691, 2013.
4). Nano Letters, 12, 3788-3792, 2012.
5). Journal of Physical Chemistry C, 116, 9750–9754, 2012.

2. Modulation & Actuating Devices

Our interest in this thrust ranges from bio-intervention devices to soft actuators.  A recent example is developing functional nanomesh based transparent and stretchable neural (or nerve) interface.  We  have demonstrated that by stacking individual layers of metal, and low-impedance coating reliably in a same nanomeshed pattern, the final bilayer nanomesh achieved system-level performance from both individual layers, in addition to nanomesh advantages.


Recent papers:
1).  Advanced Functional Materials, 1704117, 2017.
2). “Transparent Arrays of Bilayer-Nanomesh Microelectrodes for Simultaneous Electrophysiology and 2-Photon Imaging in the Brain”, submitted.

3. Electro-Catalysts

Electrochemical reactions are almost everywhere, from batteries to producing energy in every cell of every plant and animal.  In this thrust, we aim to build novel electro-catalysts from scalable nanotechnologies and understand their catalytic activities.  Besides fundamental catalytic studies and their direct applications, we are also interested in building bio-mimetic machines powered by controlled electrochemical reactions.