A robust superhydrophobic and superoleophobic surface is demonstrated. On a large-size template of the transparent polydimethylsiloxane (PDMS) elastomer surface, perfectly ordered microstructures with an inverse-trapezoidal cross section are fabricated with two consecutive PDMS replication processes and a three-dimensional diffuser lithography technique. The hydrophobicity and transparency were improved by additional coating of a fluoropolymer layer. The robustness of superhydrophobicity was confirmed by the water droplet impinging test. This transparent, flexible, and superhydrophobic surface provides a new approach for self-cleaning surfaces.

A self-cleaning effect developed through the use of a superhydrophobic and water-repellent surface was demonstrated for solar cell applications. A perfectly ordered microshell array was fabricated on a transparent and flexible polydimethylsiloxane (PDMS) elastomer surface. This microshell PDMS showed an excellent water-repellent property with a contact angle (CA) higher than 150° and a hysteresis of lower than 20°, even without the aid of a low surface energy chemical coating. Fabricated superhydrophobic microshell PDMS showed a superior dust cleaning effect compared to that of flat PDMS, preventing the degradation by dust particles of solar cell efficiency. This transparent, flexible and superhydrophobic microshell PDMS surface provides feasibility for a practical application of superhydrophobic surfaces in solar cells.

Optogenetics promises exciting neuroscience research by offering optical stimulation of neurons with unprecedented temporal resolution, cell-type specificity and the ability to excite as well as to silence neurons. This work provides the technical solution to deliver light to local neurons and record neural potentials, facilitating local circuit analysis and bridging the gap between optogenetics and neurophysiology research. We have designed and obtained the first in vivo validation of a neural probe with monolithically integrated electrodes and waveguide. High spatial precision enables optical excitation of targeted neurons with minimal power and recording of single-units in dense cortical and subcortical regions. The total coupling and transmission loss through the dielectric waveguide at 473 nm was 10.5 ± 1.9 dB, corresponding to an average output intensity of 9400 mW mm(-2) when coupled to a 7 mW optical fiber. Spontaneous field potentials and spiking activities of multiple Channelrhodopsin-2 expressing neurons were recorded in the hippocampus CA1 region of an anesthetized rat. Blue light stimulation at intensity of 51 mW mm(-2) induced robust spiking activities in the physiologically identified local populations. This minimally invasive, complete monolithic integration provides unmatched spatial precision and scalability for future optogenetics studies at deep brain regions with high neuronal density.

An underlap channel-embedded FET is proposed for electrical, label-free biosensor in both watery and dry environments, and current-voltage characteristics measured under each environment are compared. To investigate the effectiveness of the underlap device as a biosensor for both environments, antigen-antibody binding of an avian influenza (AI) is used. Antibody of AI binding on antigen-immobilized surface provides additional negative charge on underlap surface, and they give rise to channel potential increasing and result in drain current reduction. In this study, we have verified that the biosensor characteristics measured under dry environment is valid as much as they are valid for watery environment.