摘要:
A method and apparatus for identifying a sample, involves illuminating the sample with light of varying wavelengths, transmitting an acoustic signal against the sample from one portion and receiving a resulting acoustic signal on another portion, detecting a change of phase in the acoustic signal corresponding to the light of varying wavelengths, and analyzing the change of phase in the acoustic signal for the varying wavelengths of illumination to identify the sample. The apparatus has a controlled source for illuminating the sample with light of varying wavelengths, a transmitter for transmitting an acoustic wave, a receiver for receiving the acoustic wave and converting the acoustic wave to an electronic signal, and an electronic circuit for detecting a change of phase in the acoustic wave corresponding to respective ones of the varying wavelengths and outputting the change of phase for the varying wavelengths to allow identification of the sample. The method and apparatus can be used to detect chemical composition or visual features. A transmission mode and a reflection mode of operation are disclosed. The method and apparatus can be applied at nanoscale to detect molecules in a biological sample.
摘要:
A method, system, and apparatus are provided for separating molecules, such as biomolecules. The method, system, and apparatus utilize an electrochemical cell having at least two electrodes, one electrode comprising a photo-sensitive material capable of generating a photopotential. Molecules are moved through an electrolyte medium between the at least two electrodes based upon localized photopotentials.
摘要:
An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.
摘要:
Low energy light illumination and either a doped semiconductor surface or a surface-plasmon supporting surface are used in combination for manipulating a fluid on the surface in the absence of any applied electric fields or flow channels. Precise control of fluid flow is achieved by applying focused or tightly collimated low energy light to the surface-fluid interface. In the first embodiment, with an appropriate dopant level in the semiconductor substrate, optically excited charge carriers are made to move to the surface when illuminated. In a second embodiment, with a thin-film noble metal surface on a dispersive substrate, optically excited surface plasmons are created for fluid manipulation. This electrode-less optical control of the Marangoni effect provides re-configurable manipulations of fluid flow, thereby paving the way for reprogrammable microfluidic devices.
摘要:
A sensor apparatus is provided using a microcantilevered spring element having a coating of a detector molecule such as an antibody or antigen. A sample containing a target molecule or substrate is provided to the coating. The spring element bends in response to the stress induced by the binding which occurs between the detector and target molecules. Deflections of the cantilever are detected by a variety of detection techniques. The microcantilever may be approximately 1 to 200 &mgr;m long, approximately 1 to 50 &mgr;m wide, and approximately 0.3 to 3.0 &mgr;m thick. A sensitivity for detection of deflections is in the range of 0.01 nanometers.
摘要:
Methods and apparatus for detecting particular frequencies of acoustic vibration utilize an electrostatically-tunable beam element having a stress-sensitive coating and means for providing electrostatic force to controllably deflect the beam element thereby changing its stiffness and its resonance frequency. It is then determined from the response of the electrostatically-tunable beam element to the acoustical vibration to which the beam is exposed whether or not a particular frequency or frequencies of acoustic vibration are detected.
摘要:
A mass microsensor is fabricated with a microcantilever oscillated by a piezoelectric transducer. A chemical coating having absorptive or adsorptive affinity for a specifically targeted chemical or compound is applied to the microcantilever for oscillation in the monitored atmosphere. Molecules of the targeted chemical attach to the microcantilever coating resulting in an oscillating mass increase which influences the resonant frequency of the microcantilever oscillation. The rate at which the coated microcantilever accumulates the target chemical is functional of the target chemical concentration. Consequently, the extent of microcantilever oscillation frequency change is related to the concentration of the target chemical within the monitored atmosphere. Such oscillation frequency changes are detected by a center-crossing photodiode which responds to a laser diode beam reflected from the microcantilever surface resulting in an output frequency from the photodiode that is synchronous with the microcantilever frequency.
摘要:
Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.
摘要:
Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.
摘要:
A system and method are disclosed for standoff spectroscopy of molecules (e.g. from a residue) on a surface from a distance. A source emits radiation that modifies or conditions the residue, such as through photodecomposition. A spectral generating source measures a spectrum of the residue before and after the residue is exposed to the radiation from that source. The two spectra are compared to produce a distinct identification of the residues on the surface or identify certain properties of the residue.