Resting on our demonstration of laser-driven nanophotonics-based particle acceleration, we propose to build a miniature particle accelerator on a photonic chip, comprising high gradient acceleration and fully optical field-based electron control. The resulting electron beam has outstanding space-time properties: It is bunched on sub-femtosecond timescales, is nanometres wide and coherent. We aim at utilizing this new form of all-optical free electron control in a broad research program with five exciting objectives: (1) Build a 5 MeV accelerator on a photonic chip in a shoebox-sized vessel, (2) Perform ultrafast diffraction with attosecond and even zeptosecond electron pulses, (3) Generate photons on chip at various wavelengths (IR to x-ray), (4) Couple quantum-coherently electron wavepackets and light in multiple interaction zones, and (5) Conduct radiobiological experiments, akin to the new FLASH radiotherapy and Microbeam cell treat-ment. AccelOnChip will enable five science objectives potentially shifting the horizons of today’s knowledge and capabilities around ultrafast electron imaging, photon generation, (quantum) electron-light coupling, and radiotherapy dramatically. Moreover, AccelOnChip promises to democratize accelerators: the accelerator on a chip will be based on inexpensive nanofabrication technology. We foresee that every university lab can have access to particle and light sources, today only accessible at large facilities. Last, AccelOnChip will take decisive steps towards an ultracompact electron beam radiation device to be put into the tip of a catheter, a potentially disruptive radiation therapy device facilitating new treatment forms. AccelOnChip is a cross-disciplinary high risk/high return project combining and benefiting nanophotonics, accelerator science, ultra-fast physics, materials science, coherent light-matter coupling, light generation, and radiology - and is based on my group’s unique expertise acquired in recent years.

We propose the development of the chemistry of black phosphorus (BP). B-PhosphoChem will constitute a new text book chapter in the realm of synthetic chemistry located at the interface of inorganic-, organic-, and materials chemistry as well as solid state physics. B-PhosphoChem will provide the basis for exciting and so far elusive applications such as ion batteries and stable high performance devices. Thin sheets of BP represent a new class of 2D materials and have recently raised tremendous interest in the scientific community. Outstanding physical properties such as high charge carrier mobility, combined with transparency and the persistence of a band gap have been discovered. However, the chemistry of BP remains still unexplored. B-PhosphoChem will close this gap and will a) provide the opportunity to modulate and fine tune the physical properties, b) allow for considerably improving the processability and increasing the solubility, c) establish concepts for the desired chemical stabilization, d) give access to the combination of BP properties with those of other compound classes, e) reveal the fundamental chemical properties and reactivity principles, and f) provide methods for establishing practical applications. Five work packages will be addressed: 1) Production of Thin Layer BP, 2) Supramolecular Chemistry of BP, 3) Intercalation Compounds of BP, 4) Covalent Chemistry of BP, and 5) BP-Based Materials and Devices. The work packages will be supported by systematic calculations. For our group, whose core competence is synthetic organic and supramolecular chemistry, the orientation towards inorganic phosphorus chemistry constitutes a major step into a completely new direction. However, we are convinced to be the most predestinated research group in the world successfully facing this challenge because of our leadership and well documented interdisciplinary experience in synthesizing and characterizing 0D-, 1D-, and 2D nanostructures.

The ALAMS project will provide the first application of "atomic-layer additive manufacturing" (ALAM), namely for the prototyping of solar cells in large arrays of microdevices. The ALAM concept combines the principles of additive manufacturing (3D printing) with the atomic resolution achieved by the thin coating technique atomic layer deposition (ALD). In ALD, atomic-level control is achieved by judiciously designing the surface reaction chemistry of molecular precursors at near-room temperature for it to become self-limiting. This renders experimental use of ALD very robust to a wide range of parameter variations, since the film growth occurs in a cyclic, layer-by-layer mode. This advantage will be exploited towards 3D printing, an area of application that ALD has never been used for until we built the first ALAM prototype in November 2019. This prototype centers around a printhead that delivers the ALD precursors to the gas phase in the vicinity of the substrate surface, with a microfluidic element delivering a lateral resolution on the order of micrometers. The motion of the printhead with respect to the substrate allows the user to ‘print’ lines and structures of arbitrarily chosen geometries, whereby each pass over a given point of the substrate adds to it exactly the amount of material corresponding to one ALD monolayer, that is, a thickness typically on the order of an atom, or 0.1 nanometer (depending on the exact ALD reaction used). After developing the ALD chemistry needed for ALAM of the materials required to generate photovoltaic stacks, the ALAMS PoC project will apply it to a case study, namely the rapid prototyping of solar cell microdevices in large arrays. The ALAM concept, however, is valid beyond the confines of photovoltaic research. Its commercial potential stems from its position at the convergence of two highly modern, fast-growing markets, namely, additive manufacturing ('3D printing') and microelectromechanical systems (MEMS).

The emergence of a new era in neuromodulation is led by the intriguing potential of functional materials to replace or control neural activity. The ability to simultaneously analyse neural activity offers the potential to translate signals into a feedback loop for intuitive therapy or even to replace lost neurological functions. However, neuromodulation and recording in the deep brain commonly relies on chronic implantation of macroscale hardware with numerous safety concerns and often suffers from poor spatiotemporal resolution. BRAINMASTER will demonstrate scalable, wireless, minimally invasive neuromodulation relying on forces transformed to mechanosensory neurons by magnetic nanodiscs (MNDs) coupled to external magnetic fields (MFs). Neuromodulation will run concurrently with magnetic resonance imaging (MRI) of Ca2+ transients. BRAINMASTERs ambitious objectives will permit cell-type specific interrogation (write) and simultaneous imaging (read) of deep brain in untethered subjects without implanted hardware, overcoming major challenges present in existing approaches. MNDs will be engineered to selectively target neural mechanosensitive ion channels by release of viral vectors for exogenous channel expression or by recognition motifs for endogenous stimulation. MND surface with Ca2+ binding moieties will allow dynamic MRI imaging via formation of ferromagnetic clusters translated as MRI contrast variations. The bidirectional BRAINMASTER interface will include MRI Ca2+ imaging simultaneous with stimulus from large gradient forces pulling MNDs on mechanosensory cells and torques mediated by low frequency MFs from miniaturized, MRI compatible coils. Ultimately, I will develop the first-of-its-kind intuitive interface between the deep brain and an engineered system to facilitate cognitive training and therapies for developmental, neurodegenerative and mental disorders and demonstrate the technological breakthrough in the rodent model of early Alzheimers disease.