摘要:
A deflection sensor for a microcantilever includes two sets of interdigitated fingers, one (reference) set being attached to the substrate from which the microcantilever extends and the other (movable) set being attached to the tip of the microcantilever. Together the interdigitated fingers form an optical phase grating. The deflection of the microcantilever is measured by directing a light beam against the optical phase grating and detecting the intensity of the reflected light in the first (or other) component of the resulting diffraction pattern. As the microcantilever deflects, the reference and movable fingers move relative to one another creating large variations in the intensity of the zeroth and first order components of the diffraction pattern. To eliminate "1/f" noise the deflection of the microcantilever can be measured using an AC signal.
摘要:
A method for making a silicon stylus protruding through a nitride layer is used to fabricate nitride micro-apertures, silicon styluses supported by nitride cantilever arms and charge sensitive silicon styluses supported by nitride cantilever arms. The method uses an anisotropic dry etch to define the apertures of the nitride micro-apertures and the apexes of the silicon styluses. Nitride apertures made by this method are useful for supporting micro-electronics and micro-optical devices. Surface probing devices with silicon styluses supported by nitride cantilever arms have applications in AFM and STM and are particularly useful in applications that require an electrical connection between the silicon stylus and external circuitry through the cantilever arm.
摘要:
A system for scanning and measuring a surface charge of a sample immersed in a conductive medium, such as an aqueous electrolytic solution or a gel, or positioned on a conducting plate. The system has a semiconductor with a probing surface clad in a charge-sensitive layer. The probing surface moves over the sample during scanning while a bias voltage V.sub.BIAS is applied to create a depletion layer in the semiconductor and to induce the system to alter a measurable electrical property. The electrical property is monitored with the aid of a measuring device and the measurement is correlated to the sample's surface charge. In a preferred embodiment the semiconductor is a part of a cantilever structure of the type having a probing tip and the probing surface is located on the apex of the probing tip thereby enabling examination of the topology and surface charge of the sample concurrently.
摘要:
The present invention provides an apparatus and method for nucleotide or DNA sequencing by monitoring the molecular charge configuration as the DNA moves through a protein that is capable of transcribing the DNA. The apparatus and method provides a nanoscale electrometer that immobilizes the protein. The protein receives the DNA and transcribes the DNA. The nanoscale electrometer is a sensitive device that is capable of sensing and measuring the electronic charge that is released during the transcription process. The apparatus and method of the present invention further provides monitoring means that are attached to the nanoscale electrometer to monitor the electronic charge configuration as the DNA moves through the protein. Once the electronic charge configuration is established, a correlation is computed, using computing means, between the electronic charge configuration and a nucleotide signature of the DNA.
摘要:
A bimorph spiral which exhibits a shape-altering response to thermal radiation and is dimensioned to have a focussing effect on light, such as a visible light, by acting as a quasi-Fresnel element. The focussing effect varies as the shape of the bimorph spiral changes due to absorption of thermal radiation. An array of such bimorph spirals can be used for efficient, high-resolution and rapid uncooled photothermal spectroscopy.
摘要:
Methods for improving measurements of bacterial growth, such as mass, in Suspended Microchannel Resonators (SMR's). Methods include techniques to provide for bacterial growth over time in response to changing fluid environment to aid in determining parameters such as drug resistance and drug susceptibility. In particular the methods include trapping multiple bacteria in the SMR for a time period and varying the fluid to include sequences of nutrients and antibiotics, and measuring the rate of mass change of the bacteria in response to the changes in fluid composition.
摘要:
Methods and apparatus for improving measurements of particle or cell characteristics, such as mass, in Susppended Microchannel Resonators (SMR's). Apparatus include in particular designs for trapping particles in SMR's for extended measurement periods. Methods include techniques to provide differential measurements by varying the fluid density for repeated measurements on the same particle or cell.
摘要:
Methods and apparatus for improving measurements of particle or cell characteristics, such as mass, in Susppended Microchannel Resonators (SMR's). Apparatus include in particular designs for trapping particles in SMR's for extended measurement periods. Methods include techniques to provide differential measurements by varying the fluid density for repeated measurements on the same particle or cell.
摘要:
Microsystem for monitoring cell growth. A microfluidic structure is designed to allow cells to circulate therethrough and the microfluidic structure includes modules to monitor mass, mass density and fluorescence of the cell.
摘要:
Methods for improving measurements of bacterial growth, such as mass, in Suspended Microchannel Resonators (SMR's). Methods include techniques to provide for bacterial growth over time in response to changing fluid environment to aid in determining parameters such as drug resistance and drug susceptibility. In particular the methods include trapping multiple bacteria in the SMR for a time period and varying the fluid to include sequences of nutrients and antibiotics, and measuring the rate of mass change of the bacteria in response to the changes in fluid composition.