A new fluorescent arrayed biosensor has been developed to discriminate species and concentrations of target proteins by using plural different phospholipid liposome species encapsulating fluorescent molecules, utilizing differences in permeation of the fluorescent molecules through the membrane to modulate liposome-target protein interactions. This approach proposes a basically new label-free fluorescent sensor, compared with the common technique of developed fluorescent array sensors with labeling. We have confirmed a high output intensity of fluorescence emission related to characteristics of the fluorescent molecules dependent on their concentrations when they leak from inside the liposomes through the perturbed lipid membrane. After taking an array image of the fluorescence emission from the sensor using a CMOS imager, the output intensities of the fluorescence were analyzed by a principal component analysis (PCA) statistical method. It is found from PCA plots that different protein species with several concentrations were successfully discriminated by using the different lipid membranes with high cumulative contribution ratio. We also confirmed that the accuracy of the discrimination by the array sensor with a single shot is higher than that of a single sensor with multiple shots.

Vibratory force sensors are fabricated using piezoelectric capacitors on microcantilever structures for triaxial sensitivity by the individual sensor element. The cantilevers have been formed into a 3-D curved shape by controlling residual stress combination of the multilayered structure. Triaxial tactile sensitivity of the cantilever sensor is analyzed under a tactile load application onto the surface of an elastomer in which the cantilever is embedded, mimicking human skin structure. The cantilever is converse-piezoelectrically excited by an external ac voltage and three resonant modes are developed to detect the applied load vector components by the single sensor element. Resonant frequency shifts of each mode are investigated upon load applications. The results show that the frequencies vary to the three axial tactile loads independently and they can be superposed with corresponding to the superposition of the load components. The applied load vectors are estimated by resonant frequencies of the single cantilever sensor with compensating nonlinearities of the sensor response. The estimated error is less than 1.1% to the full scale of the load ±4 kPa.

Vibratory force sensors have been fabricated using piezoelectric capacitors on microcantilevers for triaxial sensitivity by a single sensor element. The cantilevers have been formed into three-dimensionally curved shape by controlling residual stress combination of the multilayered structure. Triaxial tactile sensitivity of the cantilever has been analyzed under a load application onto the surface of an elastomer in which the cantilever is embedded. The cantilever is converse-piezoelectrically excited by an external ac voltage and three resonant modes have been developed to detect the applied load vector components by individual sensor element. The applied load vectors are estimated by measured resonant frequencies of the single cantilever sensor in an error less than 1.1% to the full scale of the load 4 kPa.

Vibration mode of piezoelectric ultrasonic microsensors was investigated on buckled diaphragm structures from the viewpoint of higher order vibration modes than the fundamental one. Several vibration modes were generated on the diaphragms as the response to an ultrasound pulse, and their natural frequencies changed with increasing the buckling deflection in different rates. The natural frequencies of some modes approached each other, and the modes were accordingly superposed and degraded into a single mode in the large buckling ranges. The large buckling of the diaphragms consequently improves their vibration and thus the output waveforms.