Donglai Zhong

All Publications

• Neuromorphic sensorimotor loop embodied by monolithically integrated, low-voltage, soft e-skin. Science (New York, N.Y.) Wang, W., Jiang, Y., Zhong, D., Zhang, Z., Choudhury, S., Lai, J. C., Gong, H., Niu, S., Yan, X., Zheng, Y., Shih, C. C., Ning, R., Lin, Q., Li, D., Kim, Y. H., Kim, J., Wang, Y. X., Zhao, C., Xu, C., Ji, X., Nishio, Y., Lyu, H., Tok, J. B., Bao, Z. 2023; 380 (6646): 735-742

  Abstract

  Artificial skin that simultaneously mimics sensory feedback and mechanical properties of natural skin holds substantial promise for next-generation robotic and medical devices. However, achieving such a biomimetic system that can seamlessly integrate with the human body remains a challenge. Through rational design and engineering of material properties, device structures, and system architectures, we realized a monolithic soft prosthetic electronic skin (e-skin). It is capable of multimodal perception, neuromorphic pulse-train signal generation, and closed-loop actuation. With a trilayer, high-permittivity elastomeric dielectric, we achieved a low subthreshold swing comparable to that of polycrystalline silicon transistors, a low operation voltage, low power consumption, and medium-scale circuit integration complexity for stretchable organic devices. Our e-skin mimics the biological sensorimotor loop, whereby a solid-state synaptic transistor elicits stronger actuation when a stimulus of increasing pressure is applied.

  View details for DOI 10.1126/science.ade0086

  View details for PubMedID 37200416

• Wireless, closed-loop, smart bandage with integrated sensors and stimulators for advanced wound care and accelerated healing. Nature biotechnology Jiang, Y., Trotsyuk, A. A., Niu, S., Henn, D., Chen, K., Shih, C. C., Larson, M. R., Mermin-Bunnell, A. M., Mittal, S., Lai, J. C., Saberi, A., Beard, E., Jing, S., Zhong, D., Steele, S. R., Sun, K., Jain, T., Zhao, E., Neimeth, C. R., Viana, W. G., Tang, J., Sivaraj, D., Padmanabhan, J., Rodrigues, M., Perrault, D. P., Chattopadhyay, A., Maan, Z. N., Leeolou, M. C., Bonham, C. A., Kwon, S. H., Kussie, H. C., Fischer, K. S., Gurusankar, G., Liang, K., Zhang, K., Nag, R., Snyder, M. P., Januszyk, M., Gurtner, G. C., Bao, Z. 2022

  Abstract

  'Smart' bandages based on multimodal wearable devices could enable real-time physiological monitoring and active intervention to promote healing of chronic wounds. However, there has been limited development in incorporation of both sensors and stimulators for the current smart bandage technologies. Additionally, while adhesive electrodes are essential for robust signal transduction, detachment of existing adhesive dressings can lead to secondary damage to delicate wound tissues without switchable adhesion. Here we overcome these issues by developing a flexible bioelectronic system consisting of wirelessly powered, closed-loop sensing and stimulation circuits with skin-interfacing hydrogel electrodes capable of on-demand adhesion and detachment. In mice, we demonstrate that our wound care system can continuously monitor skin impedance and temperature and deliver electrical stimulation in response to the wound environment. Across preclinical wound models, the treatment group healed ~25% more rapidly and with ~50% enhancement in dermal remodeling compared with control. Further, we observed activation of proregenerative genes in monocyte and macrophage cell populations, which may enhance tissue regeneration, neovascularization and dermal recovery.

  View details for DOI 10.1038/s41587-022-01528-3

  View details for PubMedID 36424488

  View details for PubMedCentralID 5350204

• Realizing Intrinsically Stretchable Semiconducting Polymer Films by Nontoxic Additives ACS MATERIALS LETTERS Cheng, H., Zhang, S., Michalek, L., Ji, X., Luo, S., Cooper, C. B., Gong, H., Nikzad, S., Chiong, J. A., Wu, Y., Zheng, Y., Liu, Q., Zhong, D., Lei, Y., Tomo, Y., Wei, K., Zhou, D., Tok, J., Bao, Z. 2022; 4 (11): 2328-2336

  View details for DOI 10.1021/acsmaterialslett.2c00749

  View details for Web of Science ID 000898404900001

• Tuning the Mechanical and Electric Properties of Conjugated Polymer Semiconductors: Side-Chain Design Based on Asymmetric Benzodithiophene Building Blocks ADVANCED FUNCTIONAL MATERIALS Liu, D., Lei, Y., Ji, X., Wu, Y., Lin, Y., Wang, Y., Zhang, S., Zheng, Y., Chen, Y., Lai, J., Zhong, D., Cheng, H., Chiong, J. A., Gu, X., Gam, S., Yun, Y., Tok, J., Bao, Z. 2022

  View details for DOI 10.1002/adfm.202203527

  View details for Web of Science ID 000843763400001

• Topological supramolecular network enabled high-conductivity, stretchable organic bioelectronics. Science (New York, N.Y.) Jiang, Y., Zhang, Z., Wang, Y. X., Li, D., Coen, C. T., Hwaun, E., Chen, G., Wu, H. C., Zhong, D., Niu, S., Wang, W., Saberi, A., Lai, J. C., Wu, Y., Wang, Y., Trotsyuk, A. A., Loh, K. Y., Shih, C. C., Xu, W., Liang, K., Zhang, K., Bai, Y., Gurusankar, G., Hu, W., Jia, W., Cheng, Z., Dauskardt, R. H., Gurtner, G. C., Tok, J. B., Deisseroth, K., Soltesz, I., Bao, Z. 2022; 375 (6587): 1411-1417

  Abstract

  Intrinsically stretchable bioelectronic devices based on soft and conducting organic materials have been regarded as the ideal interface for seamless and biocompatible integration with the human body. A remaining challenge is to combine high mechanical robustness with good electrical conduction, especially when patterned at small feature sizes. We develop a molecular engineering strategy based on a topological supramolecular network, which allows for the decoupling of competing effects from multiple molecular building blocks to meet complex requirements. We obtained simultaneously high conductivity and crack-onset strain in a physiological environment, with direct photopatternability down to the cellular scale. We further collected stable electromyography signals on soft and malleable octopus and performed localized neuromodulation down to single-nucleus precision for controlling organ-specific activities through the delicate brainstem.

  View details for DOI 10.1126/science.abj7564

  View details for PubMedID 35324282

• High-brightness all-polymer stretchable LED with charge-trapping dilution. Nature Zhang, Z., Wang, W., Jiang, Y., Wang, Y., Wu, Y., Lai, J., Niu, S., Xu, C., Shih, C., Wang, C., Yan, H., Galuska, L., Prine, N., Wu, H., Zhong, D., Chen, G., Matsuhisa, N., Zheng, Y., Yu, Z., Wang, Y., Dauskardt, R., Gu, X., Tok, J. B., Bao, Z. 2022; 603 (7902): 624-630

  Abstract

  Next-generation light-emitting displays on skin should be soft, stretchable and bright1-7. Previously reported stretchable light-emitting devices were mostly basedon inorganic nanomaterials, such as light-emitting capacitors, quantum dots or perovskites6-11. They either require high operating voltage or have limited stretchability and brightness, resolution or robustness under strain. On the other hand, intrinsically stretchable polymer materials hold the promise of good strain tolerance12,13. However, realizing high brightness remains a grand challenge for intrinsically stretchable light-emitting diodes. Here we report a material design strategy and fabrication processes to achieve stretchable all-polymer-based light-emitting diodes with high brightness (about 7,450candela per square metre), current efficiency (about 5.3candela per ampere) and stretchability (about 100per cent strain). We fabricate stretchable all-polymer light-emitting diodes coloured red, green and blue, achieving both on-skin wireless powering and real-time displaying of pulse signals. This work signifies a considerable advancement towards high-performance stretchable displays.

  View details for DOI 10.1038/s41586-022-04400-1

  View details for PubMedID 35322250

• A molecular design approach towards elastic and multifunctional polymer electronics. Nature communications Zheng, Y., Yu, Z., Zhang, S., Kong, X., Michaels, W., Wang, W., Chen, G., Liu, D., Lai, J., Prine, N., Zhang, W., Nikzad, S., Cooper, C. B., Zhong, D., Mun, J., Zhang, Z., Kang, J., Tok, J. B., McCulloch, I., Qin, J., Gu, X., Bao, Z. 2021; 12 (1): 5701

  Abstract

  Next-generation wearable electronics require enhanced mechanical robustness and device complexity. Besides previously reported softness and stretchability, desired merits for practical use include elasticity, solvent resistance, facilepatternability and high charge carrier mobility. Here, we show a molecular design concept that simultaneously achieves all these targeted properties in both polymeric semiconductors and dielectrics, without compromising electrical performance. This is enabled by covalently-embedded in-situ rubber matrix (iRUM) formation through good mixing of iRUM precursors with polymer electronic materials, and finely-controlled composite film morphology built on azide crosslinking chemistry which leverages different reactivities with C-H and C=C bonds. The high covalent crosslinking density results in both superior elasticity and solvent resistance. When applied in stretchable transistors, the iRUM-semiconductor film retained its mobility after stretching to 100% strain, and exhibited record-high mobility retention of 1 cm2 V-1 s-1 after 1000 stretching-releasing cycles at 50% strain. The cycling life was stably extended to 5000 cycles, five times longer than all reported semiconductors. Furthermore, we fabricated elastic transistors via consecutively photo-patterning of the dielectric and semiconducting layers, demonstrating the potential of solution-processed multilayer device manufacturing. The iRUM represents a molecule-level design approach towards robust skin-inspired electronics.

  View details for DOI 10.1038/s41467-021-25719-9

  View details for PubMedID 34588448

• A Design Strategy for Intrinsically Stretchable High-Performance Polymer Semiconductors: Incorporating Conjugated Rigid Fused-Rings with Bulky Side Groups. Journal of the American Chemical Society Liu, D., Mun, J., Chen, G., Schuster, N. J., Wang, W., Zheng, Y., Nikzad, S., Lai, J., Wu, Y., Zhong, D., Lin, Y., Lei, Y., Chen, Y., Gam, S., Chung, J. W., Yun, Y., Tok, J. B., Bao, Z. 2021

  Abstract

  Strategies to improve stretchability of polymer semiconductors, such as introducing flexible conjugation-breakers or adding flexible blocks, usually result in degraded electrical properties. In this work, we propose a concept to address this limitation, by introducing conjugated rigid fused-rings with optimized bulky side groups and maintaining a conjugated polymer backbone. Specifically, we investigated two classes of rigid fused-ring systems, namely, benzene-substituted dibenzothiopheno[6,5-b:6',5'-f]thieno[3,2-b]thiophene (Ph-DBTTT) and indacenodithiophene (IDT) systems, and identified molecules displaying optimized electrical and mechanical properties. In the IDT system, the polymer PIDT-3T-OC12-10% showed promising electrical and mechanical properties. In fully stretchable transistors, the polymer PIDT-3T-OC12-10% showed a mobility of 0.27 cm2 V-1 s-1 at 75% strain and maintained its mobility after being subjected to hundreds of stretching-releasing cycles at 25% strain. Our results underscore the intimate correlation between chemical structures, mechanical properties, and charge carrier mobility for polymer semiconductors. Our described molecular design approach will help to expedite the next generation of intrinsically stretchable high-performance polymer semiconductors.

  View details for DOI 10.1021/jacs.1c04984

  View details for PubMedID 34284578

• Monolithic optical microlithography of high-density elastic circuits. Science (New York, N.Y.) Zheng, Y. Q., Liu, Y., Zhong, D., Nikzad, S., Liu, S., Yu, Z., Liu, D., Wu, H. C., Zhu, C., Li, J., Tran, H., Tok, J. B., Bao, Z. 2021; 373 (6550): 88-94

  Abstract

  Polymeric electronic materials have enabled soft and stretchable electronics. However, the lack of a universal micro/nanofabrication method for skin-like and elastic circuits results in low device density and limited parallel signal recording and processing ability relative to silicon-based devices. We present a monolithic optical microlithographic process that directly micropatterns a set of elastic electronic materials by sequential ultraviolet light-triggered solubility modulation. We fabricated transistors with channel lengths of 2 micrometers at a density of 42,000 transistors per square centimeter. We fabricated elastic circuits including an XOR gate and a half adder, both of which are essential components for an arithmetic logic unit. Our process offers a route to realize wafer-level fabrication of complex, high-density, and multilayered elastic circuits with performance rivaling that of their rigid counterparts.

  View details for DOI 10.1126/science.abh3551

  View details for PubMedID 34210882

• High-frequency and intrinsically stretchable polymer diodes. Nature Matsuhisa, N., Niu, S., O'Neill, S. J., Kang, J., Ochiai, Y., Katsumata, T., Wu, H., Ashizawa, M., Wang, G. N., Zhong, D., Wang, X., Gong, X., Ning, R., Gong, H., You, I., Zheng, Y., Zhang, Z., Tok, J. B., Chen, X., Bao, Z. 2021; 600 (7888): 246-252

  Abstract

  Skin-like intrinsically stretchable soft electronic devices are essential to realize next-generation remote and preventative medicine for advanced personal healthcare1-4. The recent development of intrinsically stretchable conductors and semiconductors has enabled highly mechanically robust and skin-conformable electronic circuits or optoelectronic devices2,5-10. However, their operating frequencies have been limited to less than 100hertz, which is much lower than that required for many applications. Here we report intrinsically stretchable diodes-based on stretchable organic and nanomaterials-capable of operating at a frequency as high as 13.56megahertz. This operating frequency is high enough for the wireless operation of soft sensors and electrochromicdisplaypixels using radiofrequency identification in which the base-carrier frequency is 6.78megahertz or13.56megahertz. This was achieved through a combination of rational material design and device engineering. Specifically, we developed a stretchable anode, cathode, semiconductor and current collector that can satisfy the strict requirements for high-frequency operation. Finally, we show the operational feasibility of our diode by integrating it with a stretchable sensor, electrochromicdisplay pixel and antenna to realize a stretchable wireless tag. This work is an important step towards enabling enhanced functionalities and capabilities for skin-like wearable electronics.

  View details for DOI 10.1038/s41586-021-04053-6

  View details for PubMedID 34880427