Kwan H. Lee

We investigate the evolution of the vertical morphology in a solution-processed P3HT/PCBM “bilayer” organic solar cell using a combination of techniques, including neutron reflectometry. By correlating the device performance with the active layer morphology, we establish that the solution processed bilayer concept is a misnomer and sequential solution processing is an elegant way to make bulk heterojunction organic solar cells with high efficiency.

We implement a cavity optoelectromechanical system integrating electrical actuation capabilities of nanoelectromechanical devices with ultrasensitive mechanical transduction achieved via intracavity optomechanical coupling. Electrical gradient forces as large as 0.40 microN are realized, with simultaneous mechanical transduction sensitivity of 1.5x10{-18} m Hz{-1/2} representing a 3 orders of magnitude improvement over any nanoelectromechanical system to date. Optoelectromechanical feedback cool

Screening for prostate cancer relies on the serum prostate-specific antigen test, which provides a high rate of false positives (80%). This results in a large number of unnecessary biopsies and subsequent overtreatment. Considering the frequency of the test, there is a critical unmet need of precision screening for prostate cancer. Here, we introduced a urinary multimarker biosensor with a capacity to learn to achieve this goal. The correlation of clinical state with the sensing signals from uri

Bacteriophages are traditionally used for the development of phage display technology. Recently, their nanosized dimensions and ease with which genetic modifications can be made to their structure and function have put them in the spotlight towards their use in a variety of biosensors. In particular, the expression of any protein or peptide on the extraluminal surface of bacteriophages is possible by genetically engineering the genome. In addition, the relatively short replication time of bacter

There is an explosive interest in the immediate and cost-effective analysis of field-collected biological samples, as many advanced biodetection tools are highly sensitive, yet immobile. On-site biosensors are portable and convenient sensors that provide detection results at the point of care. They are designed to secure precision in highly ionic and heterogeneous solutions with minimal hardware. Among various methods that are capable of such analysis, field-effect biosensors are promising candi

Ion-sensitive field-effect transistors (ISFETs), although they have attracted considerable attention as effective immunosensors, have still not been adopted for practical applications owing to several problems: (1) the poor sensitivity caused by the short Debye screening length in media with high ion concentration, (2) time-consuming preconditioning processes for achieving the highly-diluted media, and (3) the low durability caused by undesirable ions such as sodium chloride in the media. Here,