Jae Sung Son

Soft as silk: Single-layered (right) and lamellar-structured two-dimensional (2D) CdSe nanocrystals (left) as thin as 1.4 nm can be prepared by a soft colloidal template method. Assembly of the 2D nanocrystals can be controlled by variation of the interaction between organic layers in soft templates. The current synthetic process is relatively easy to scale up, and multigram quantities can be obtained in a single batch. Detailed facts of importance to specialist readers are published as ”Support

We herein report on the large-scale synthesis of ultrathin Bi(2)Te(3) nanoplates and subsequent spark plasma sintering to fabricate n-type nanostructured bulk thermoelectric materials. Bi(2)Te(3) nanoplates were synthesized by the reaction between bismuth thiolate and tri-n-octylphosphine telluride in oleylamine. The thickness of the nanoplates was ~1 nm, which corresponds to a single layer in Bi(2)Te(3) crystals. Bi(2)Te(3) nanostructured bulk materials were prepared by sintering of surfactant-

2D semiconductor quantum wells have been recognized as potential candidates for various quantum devices. In quantum wells, electrons and holes are spatially confined within a finite thickness and freely move in 2D space. Much effort has focused on shape control of colloidal semiconductor nanocrystals(NCs), and synthesis of 2D colloidal NCs has been achieved very recently. Here, recent advances in colloidal synthesis of uniform and ultrathin 2D CdSeNCs are highlighted. Structural and optical prop

This paper presents a tactile sensor that provides transient event information at the finger-object interface. The multi-element stress rate sensor consists of piezoelectric polymer strips moulded into the surface of the rubber "skin" covering the robot finger tip. These piezoelectric elements provide localized information important to manipulation control. We provide experimental results confirming the sensor's ability to detect three parameters. Contact events have been detected for signaling

The dimension-controlled synthesis of CdS nanocrystals in the strong quantum confinement regime is reported. Zero-, one-, and two-dimensional CdS nanocrystals are selectively synthesized via low-temperature reactions using alkylamines as surface-capping ligands. The shape of the nanocrystals is controlled systematically by using different amines and reaction conditions. The 2D nanoplates have a uniform thickness as low as 1.2 nm. Furthermore, their optical absorption and emission spectra show ve

Thermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu₂Se thermoelectric materials. We design the optimum aspect rat

Pressed Bi nanocrystals synthesized by a simple colloidal method exhibited very high electrical conductivity of 104–105 S m−1 and extremely low thermal conductivity of 0.35 W m−1 K−1. The synthetic method can be used for the inexpensive preparation of highly efficient thermoelectric materials by engineering the size of nanocrystals (see picture; scale bar 50 nm; ZT=figure of merit). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are p

The growing concern over the depletion of hydrocarbon resources, and the adverse environmental effects associated with their use, has increased the demand for renewable energy sources. Thermoelectric (TE) power generation from waste heat has emerged as a renewable energy source that does not generate any pollutants. Recently, ink-based processing for the preparation of TE materials has attracted tremendous attention because of the simplicity in design of power generators and the possibility of c

Seidenweich: CdSe-Nanoblätter (rechts) und lamellare zweidimensionale CdSe-Nanokristalle (links) mit nur 1.4 nm Dicke werden durch eine Kolloidsynthese erhalten. Der Aufbau der zweidimensionalen Nanokristalle lässt sich durch Variation der Wechselwirkung zwischen organischen Schichten in den weichen Templaten steuern. Eine Maßstabsvergrößerung ist leicht möglich, sodass mehrere Gramm des Produkts auf einmal erhältlich sind.

Nano- and mesostructuring is widely used in thermoelectric (TE) materials. It introduces numerous interfaces and grain boundaries that scatter phonons and decrease thermal conductivity. A new approach has been developed for the rational design of the interfaces in TE materials by using all-inorganic nanocrystals (NCs) that serve as a "glue" for mesoscopic grains. For example, circa 10 nm Bi NCs capped with (N2H5)4Sb2Te7 chalcogenidometallate ligands can be used as an additive to BiSbTe particles

Owing to the increase in the demand for energy autonomy in electronic systems, there has been increased research interest in thermoelectric thin-film-based energy harvesters. However, the fabrication of such devices is challenging when considering material performance and integration processes. SnSe has emerged as among the best bulk thermoelectric materials capable of functioning at high temperatures; however, the thermoelectric performance of thin films is still limited. Herein, we present a s

In this paper we analyze and experimentally measure the benefits of tactile sensing for stiffness control in the presence of uncertainty. There are two parts of the manipulation process where tactile information is helpful: determining the initial object pose as the fingers close to grasp, and tracking the object as it rolls and slides against the fingers during manipulation. The paper begins with an analysis of uncertainty associated with the initial orientation of a grasped object. We then rev

A new approach to increasing the output voltage of a thermoelectric generator that does not involve material modification is demonstrated. The key component of the device is a dielectric layer and a metal layer with an air gap between them, attached at the cold side of a thermoelectric generator with a Cu/p-type BiSbTe/Au/Cr/SiO2/Si composition. When the two layers contact each other, negative charges are created on the dielectric surface, causing the electric potential difference across the two