Biologically inspired ultrathin arrayed camera for high-contrast and high-resolution imaging

Compound eyes found in insects provide intriguing sources of biological inspiration for miniaturised imaging systems.Here,we report an ultrathin arrayed camera inspired by insect eye structures for high-contrast and super-resolution imaging.The ultrathin camera features micro-optical elements(MOEs),i.e.,inverted microlenses,multilayered pinhole arrays,and gap spacers on an image sensor.The MOE was fabricated by using repeated photolithography and thermal reflow.The fully packaged camera shows a total track length of 740μm and a field-of-view(FOV)of 73°.The experimental results demonstrate that the multilayered pinhole of the MOE allows high-contrast imaging by eliminating the optical crosstalk between microlenses.The integral image reconstructed from array images clearly increases the modulation transfer function(MTF)by~1.57 times compared to that of a single channel image in the ultrathin camera.This ultrathin arrayed camera provides a novel and practical direction for diverse mobile,surveillance or medical applications.

Xenos peckii vision inspires an ultrathin digital camera

Increased demand for compact devices leads to rapid development of miniaturized digital cameras.However,conventional camera modules contain multiple lenses along the optical axis to compensate for optical aberrations that introduce technical challenges in reducing the total thickness of the camera module.Here,we report an ultrathin digital camera inspired by the vision principle of Xenos peckii,an endoparasite of paper wasps.The male Xenos peckii has an unusual visual system that exhibits distinct benefits for high resolution and high sensitivity,unlike the compound eyes found in most insects and some crustaceans.The biologically inspired camera features a sandwiched configuration of concave microprisms,microlenses,and pinhole arrays on a flat image sensor.The camera shows a field-of-view(FOV)of 68 degrees with a diameter of 3.4mm and a total track length of 1.4mm.The biologically inspired camera offers a new opportunity for developing ultrathin cameras in medical,industrial,and military fields.

Silver nanoislands on cellulose fibers for chromatographic separation and ultrasensitive detection of small molecules

High-throughput small-molecule assays play essential roles in biomedical diagnosis,drug discovery,environmental analysis,and physiological function research.Nanoplasmonics holds a great potential for the label-free detection of small molecules at extremely low concentrations.Here,we report the development of nanoplasmonic paper(NP-paper)for the rapid separation and ultrasensitive detection of mixed small molecules.NP-paper employs nanogap-rich silver nanoislands on cellulose fibers,which were simply fabricated at the wafer level by using low-temperature solid-state dewetting of a thin silver film.The nanoplasmonic detection allows for the scalable quantification and identification of small molecules over broad concentration ranges.Moreover,the combination of chromatographic separation and nanoplasmonic detection allows both the highly sensitive fluorescence detection of mixed small molecules at the attogram level and the label-free detection at the sub-nanogram level based on surface-enhanced Raman scattering.This novel material provides a new diagnostic platform for the high-throughput,low-cost,and label-free screening of mixed small molecules as an alternative to conventional paper chromatography.

Handheld endomicroscope using a fiber-optic harmonograph enables real-time and in vivo confocal imaging of living cell morphology and capillary perfusion

Confocal laser endomicroscopy provides high potential for noninvasive and in vivo optical biopsy at the cellular level.Here,we report a fully packaged handheld confocal endomicroscopic system for real-time,high-resolution,and in vivo cellular imaging using a Lissajous scanning fiber-optic harmonograph.The endomicroscopic system features an endomicroscopic probe with a fiber-optic harmonograph,a confocal microscope unit,and an image signal processor.The fiber-optic harmonograph contains a single mode fiber coupled with a quadrupole piezoelectric tube,which resonantly scans both axes at~1 kHz to obtain a Lissajous pattern.The fiber-optic harmonograph was fully packaged into an endomicroscopic probe with an objective lens.The endomicroscopic probe was hygienically packaged for waterproofing and disinfection of medical instruments within a 2.6-mm outer diameter stainless tube capable of being inserted through the working channel of a clinical endoscope.The probe was further combined with the confocal microscope unit for indocyanine green imaging and the image signal processor for high frame rate and high density Lissajous scanning.The signal processing unit delivers driving signals for probe actuation and reconstructs confocal images using the auto phase matching process of Lissajous fiber scanners.The confocal endomicroscopic system was used to successfully obtain human in vitro fluorescent images and real-time ex vivo and in vivo fluorescent images of the living cell morphology and capillary perfusion inside a single mouse.