Fabrication of Heterogeneous Nanogaps for Characterizing Electrochemical Metal Deposition Processes

We present a much simpler and high-throughput method compared to mechanically break junctions (MBJ) and electro-migration, to produce a heterogeneous nanogap, directly using electron beam lithography and metal lift-off technology. Au – Pt and Au – Pt silicide electrodes pairs are fabricated using two-step electron beam lithography. The shape of the electrode apex and the distance between the electrodes are well controlled

In-Plane Fabricated Insulated Gold-Tip Probe For Electrochemical And Molecular Experiments

In this contribution we present a scanning probe with a gold-tip completely encapsulated with insulator all the way to the apex. The probe fabrication is unique owing to an in-plane arrangement in which the width of the cantilever is defined by deep reactive ion etching (DRIE). E-beam lithography was employed for defining the gold nanowire tip. The cantilever and the chip body were defined by DRIE in later steps. The radius of curvature of the tip apex is around 20 nm. The high-quality insulation on the tip was demonstrated by performing electrodeposition of gold. The spring constant of the cantilever was obtained by measuring the resonance frequency of the cantilever. With this in-plane fabrication process, probes with different spring constants ranging from 0.1 N/m to 9 N/m were fabricated on the same wafer

In-plane fabrication of insulated gold-tip probes for electrochemical and force spectroscopy molecular experiments

A new and versatile fabrication process of insulated gold tip probes for atomic force microscopy (AFM) is presented by Wu et al. (In-plane fabricated insulated gold-tip probe for electrochemical and molecular experiments, in: 2013 IEEE 26th International Conference on Micro Electro Mechanical Systems (MEMS), IEEE, 2013, pp. 492-495). The novelty of the process lies in the fact that the length and the thickness of the cantilever are defined by photolithography and Si etching from the wafer top surface. Width of the cantilever is defined by the device layer of a silicon-on-insulator (SOI) wafer. The tip is fabricated in the wafer top plane. E-beam lithography was employed outlining the gold nanowire tip. The chip body is formed with the handling layer of the SOI by deep reactive ion etching in later steps. In a practical operation, the probe chip is rotated by 90 degree. The tip radius of curvature is approximately 20 nm. The high-quality insulation on the probe was demonstrated by performing electrodeposition of gold on the tip-end. The spring constant of the cantilever was obtained by measuring resonance frequency of the cantilever. With this in-plane fabrication process, probes with different spring constants ranging from 0.05 N/m to 13.67 N/m were fabricated on the same wafer. (C) 2013 Elsevier B.V. All rights reserved

Heparin Increases Food Intake through AgRP Neurons

Although the widely used anticoagulant drug heparin has been shown to have many other biological functions independent of its anticoagulant role, its effects on energy homeostasis are unknown. Here, we demonstrate that heparin level is negatively associated with nutritional states and that heparin treatment increases food intake and body weight gain. By using electrophysiological, pharmacological, molecular biological, and chemogenetic approaches, we provide evidence that heparin increases food intake by stimulating AgRP neurons and increasing AgRP release. Our results support a model whereby heparin competes with insulin for insulin receptor binding on AgRP neurons, and by doing so it inhibits FoxO1 activity to promote AgRP release and feeding. Heparin may be a potential drug target for food intake regulation and body weight control