We present high-speed force probes with on-chip actuation and sensing for the measurement of pN-scale forces at the microsecond time scale. We achieve a high resonant frequency in water (1-100 kHz) with requisite low spring constants (0.3-40 pN/nm) and low integrated force noise (1-100 pN) by targeting probe dimensions on the order of 300 nm thick, 1-2 μm wide and 30-200 μm long. Forces are measured using silicon piezoresistors while the probes are actuated thermally with an aluminum unimorph and silicon heater. The piezoresistive sensors are designed using open source numerical optimization code that incorporates constraints on operating temperature. Parylene passivation enables operation in ionic media and we demonstrate simultaneous actuation and sensing. The improved design and fabrication techniques that we describe enable a 10-20 fold improvement in force resolution or measurement bandwidth over prior piezoresistive cantilevers of comparable thickness.
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http://dx.doi.org/10.1088/0960-1317/22/9/095012 | DOI Listing |
Int J Biol Macromol
January 2025
Departmento de Biofísica e Radiobiologia, Universidade Federal de Pernambuco, Recife, Pernambuco 50670-901, Brazil. Electronic address:
Mannose-binding lectin (MBL) is an important glycoprotein of the human innate immune system. Furthermore, individuals with sickle cell anemia (SCA) and MBL deficiency seem more susceptible to vaso-occlusive crises, suggesting an MBL role on HbSS red blood cells (RBCs). This study investigated the interaction of MBL with HbA (healthy) and HbSS RBCs using optical tweezers (OT) and atomic force microscopy (AFM).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics & Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai, 200241, China.
Controlling polarization states of ferroelectrics can enrich optoelectronic properties and functions, offering a new avenue for designing advanced electronic and optoelectronic devices. Here, ferroelectric semiconductor-based field-effect transistors (FeSFETs) are fabricated, where the channel is a ferroelectric semiconductor (e.g.
View Article and Find Full Text PDFACS Nano
January 2025
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, China.
Electron transfer is ubiquitous in many chemical reactions and biological phenomena; however, the spatial heterogeneities of electron transfer kinetics in electrocatalysis are so far insufficiently resolved. Measuring and understanding the localized electron transfer are crucial to deciphering the intrinsic activity of electrocatalysts and to achieving further improvements in performance. By using scanning electrochemical probe microscopy to spatially resolve redox electrochemistry across the single-crystalline surface of gold microplates, we discover an intriguing radially distributed electron transfer pattern, where the kinetics around the periphery region are significantly higher than those at the central region, regardless of the redox reaction types.
View Article and Find Full Text PDFHeliyon
January 2025
College of Chemical Engineering, Zhejiang University of Technology, China.
Titania (TiO) is one of promising photo catalysts for its high ability to resistant photo corrosion and environmental friendliness, but its photocatalytic activity is too low to be used in industry. To find an approach to solve this problem, graphene oxide (GO), tungsten trioxide (WO) and TiO composite with hollow mesoporous structure was prepared by a two-step spray drying method. The composite was used as raw material to constitute a membrane onto ITO glass to form a membrane photo-anode.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
Deep eutectic solvents (DESs) have emerged as solubilizing media of intense interest due partly to their easily tailorable physicochemical properties. Extensive H-bonding between the constituents in a two-constituent system is the major driving force for the formation of the DES. Addition of ethanolamine (MEA), a compound having H-bonding capabilities, to the DESs composed of a terpene [menthol (Men) or thymol (Thy)] and a fatty acid [-decanoic acid (DA)] results in an unprecedented increase in dynamic viscosity due to the extensive rearrangement in the H-bonding network and other interactions within the system, while the liquid mixture still behaves as a Newtonian fluid.
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