Selective Pulsed Chemical Vapor Deposition of Water-Free TiO2/Al2O3 and HfO2/Al2O3 Nanolaminates on Si and SiO2 in Preference to SiCOH.

Highly selective and smooth TiO2/Al2O3 and HfO2/Al2O3 nanolaminates were deposited by water-free pulsed chemical vapor deposition (CVD) at 300 °C using titanium isopropoxide (Ti(OiPr)4) and hafnium tertbutoxide (Hf(OtBu)4) with trimethylaluminum (TMA). TMA was found to be the key factor for enhancing nucleation selectivity on SiO2 or Si versus SiCOH (hydrophobic, nonporous low k dielectric). With precise dosing of TMA, selective nucleation of TiO2/Al2O3 and HfO2/Al2O3 nanolaminates was achieved and smoother films were formed with higher selectivity compared to single precursor TiO2 and HfO2 CVD. The selectivity of TiO2/Al2O3 nanolaminate deposition increased from 34 to 44 (deposition on Si vs SiCOH), while RMS roughness of the film of Si decreased from 2.8 to 0.38 nm. The selectivity of HfO2/Al2O3 deposition increased from 14 to 73, while the RMS roughness of HfO2/Al2O3 on Si was maintained at a similar value of 0.78 nm. Deposition of water-free pulsed CVD TiO2/Al2O3 and HfO2/Al2O3 nanolaminates was conducted on a Cu/SiCOH patterned sample to study their nanoselectivity. Transmission electron microscopy images of the Cu/SiCOH patterned sample demonstrated that highly selective and smooth TiO2/Al2O3 and HfO2/Al2O3 nanolaminates can be formed on a nanoscale pattern.

A surgical navigated cutting guide for mandibular osteotomies: accuracy and reproducibility of an image-guided mandibular osteotomy.

PURPOSE: 3D-printed cutting guides are the current standard to translate the virtual surgery plan to the intraoperative setting. The production of these patient-specific cutting guides is time-consuming and costly, and therefore, alternative approaches are currently subject of research. The aim of this study was to assess the accuracy and reproducibility of using a novel electromagnetic (EM) navigated surgical cutting guide to perform virtually planned osteotomies in mandible models. METHODS: A novel 3D navigated cutting guide (dubbed Bladerunner) was designed and evaluated with a total of 20 osteotomies, performed on plaster mandibular models according to preoperative planning using EM navigation. The pre- and postoperative scans were registered, and the difference between the preoperatively planned osteotomy and the performed osteotomy was expressed as the distance between the planned and performed cutting planes, and the yaw and roll angles between the planes. RESULTS: The mean difference in distance between the planned osteotomy and performed osteotomy was 1.1 mm (STD 0.6 mm), the mean yaw was 1.8° (STD 1.4°), and mean roll was 1.6° (STD 1.3°). CONCLUSION: The proposed EM navigated cutting guide for mandibular osteotomies demonstrated accurate positioning of the cutting plane according to the preoperative virtual surgical plan with respect to distance, yaw and roll angles. This novel approach has the potential to make the use of 3D-printed cutting guides obsolete, thereby decreasing the interval between diagnosis and surgery, reduce cost and allow for adaptation of the virtual plan in case of rapid tumor proliferation or unanticipated in situ deviations from the preoperative CT/MR imaging.

Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip.

Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe2+) and ferric (Fe3+) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.