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Sensing and recognizing invisible ultraviolet (UV) light is vital for exploiting advanced artificial visual perception system. However, due to the uncertainty of the natural environment, the UV signal is very hard to be detected and perceived. Here, inspired by the tetrachromatic visual system, we report a controllable UV-ultrasensitive neuromorphic vision sensor (NeuVS) that uses organic phototransistors (OPTs) as the working unit to integrate sensing, memory and processing functions. Benefiting from asymmetric molecular structure and unique UV absorption of the active layer, the as fabricated UV-ultrasensitive NeuVS can detect 370 nm UV-light with the illumination intensity as low as 31 nW cm−2, exhibiting one of the best optical figures of merit in UV-sensitive neuromorphic vision sensors. Furthermore, the NeuVS array exbibits good image sensing and memorization capability due to its ultrasensitive optical detection and large density of charge trapping states. In addition, the wavelength-selective response and multi-level optical memory properties are utilized to construct an artificial neural network for extract and identify the invisible UV information. The NeuVS array can perform static and dynamic image recognition from the original color image by filtering red, green and blue noise, and significantly improve the recognition accuracy from 46 to 90%.

Grasp estimation is a fundamental technique crucial for robot manipulation tasks. In this work, we present a scene-oriented grasp estimation scheme taking constraints of the grasp pose imposed by the environment into consideration and training on samples satisfying the constraints. We formulate valid grasps for a parallel-jaw gripper as vectors in a two-dimensional (2D) image and detect them with a fully convolutional network that simultaneously estimates the vectors’ origins and directions. The detected vectors are then converted to 6 degree-of-freedom (6-DOF) grasps with a tailored strategy. As such, the network is able to detect multiple grasp candidates from a cluttered scene in one shot using only an RGB image as input. We evaluate our approach on the GraspNet-1Billion dataset and archived comparable performance as state-of-the-art while being efficient in runtime.

Boron (B)- and sulfur (S)-doped polycyclic aromatic hydrocarbons (PAHs) are developed as a novel kind of multiple resonance emitters for ultrapure blue thermally activated delayed fluorescence (TADF) polymers with narrowband electroluminescence. The combination of electron-deficient B atom and electron-rich S atom in PAH can form an intramolecular push-pull electronic system in a rigid aromatic framework, leading to reduced singlet-triplet energy splitting and limited structure relaxation of excited states. The critical roles of S atom in determining emission properties with respect to the oxygen analogues are in two aspects: (i) reducing energy bandgap to shift emission from human-eye-insensitive ultraviolet zone to blue region, and (ii) promoting reverse intersystem crossing process by heavy-atom effect to activate TADF effect. The resulting polymer containing B,S-doped PAH as emitter and acridan as host exhibits efficient blue electroluminescence at 458 nm with small full-width at half-maximum of 31 nm, representing the first example for ultrapure TADF polymer with narrowband electroluminescence.

Three acceptor-donor-acceptor (A-D-A) conjugated oligomers, i.e., O1, O2 and O3, have been synthesized using diketopyrrolopyrrole (DPP) as an electron-acceptor unit, and naphtho[1,2-b:5,6-b’]dithiophene (NDT), anthra[1,2-b:5,6-b’]dithiophene (ADT) or dithieno[3,2-b:3’,2’-b’]naphtho[1,2-b:5,6-b’]dithiophene (DTNDT) as electron-donor unit. These oligomers exhibit identical highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, which were ca. −5.1 and −3.3 eV, respectively. Upon thermal annealing, all three oligomers formed thin films with ordered microstructures, and their organic thin film transistors (OTFTs) exhibited p-type transport behavior. The mobility was increased with an extension of the size of D-units. O3 showed the best OTFT performance with the mobility of up to 0.20 cm2·V−1·s−1. The film quality of O3 was improved by adding 1 wt% poly(methylmethacrylate) (PMMA). In consequence, the mobility of the O3-based devices was further enhanced to 0.30 cm2·V−1·s−1.