The Chair for Digital Building Technologies invites applications for a PhD position on the 3D printing of stone for the restoration of heritage buildings. The doctorate rests on two closely coupled lines of work: the development of a new powder-bed printing system with spatially graded material deposition, and its use to produce replacement parts for historic stone structures. This PhD is part of the collaborative ETH Grant project "Spatially graded 3D printing to elucidate contour scaling of building stones", and will be conducted in close exchange with a second doctoral researcher at the Chair for Physical Chemistry of Building Materials in the Department of Civil, Environmental and Geomatic Engineering.

Stone is among the oldest building materials, and among the least controllable: its properties are found in the quarry, not designed. Restoration exposes this limitation acutely. A replacement part must be compatible with the original and must enter a dialogue with a structure that has aged for centuries. With historic quarries largely exhausted, selecting and carving natural blocks falls short on every one of these counts.

This project pursues a different premise: that the material properties of stone can become a design medium. The powder-bed printing platform developed at the chair separates aggregates, powder binders, and liquid activators, placing each under independent control during fabrication. The next step, and the technical core of this doctorate, is to vary these constituents within a single piece. A dual powder feed and a dual liquid feed will allow composition, porosity, and appearance to be graded continuously across a printed element, turning a fabrication process into an instrument for specifying material behavior point by point. The machine and the artifacts it produces will be developed together, each iteration informing the next.

The project is conducted jointly with a materials science group investigating deterioration mechanisms of particular concern to sandstones, whose research depends on printed samples with precisely engineered defects and gradients. The capabilities established at the laboratory scale are intended to be transferred to the chair's architectural-scale printer, where graded deposition opens a new design space for façade systems.

• You will design, build, and commission a laboratory-scale powder-bed printer with dual powder and dual liquid feeds, derived from the chair's architectural-scale system and conceived as a modular research instrument, to be reconfigured as the printed work poses new questions to the machine
• You will use it to produce stone replacement parts for heritage buildings, elements that satisfy the compatibility requirements of conservation practice while entering a dialogue with the historic fabric they join
• You will develop tectonic strategies for connecting printed parts to the existing structure, and investigate through making how a printed element addresses the surface it meets, with graded color, texture, and printed veining among the means available
• Your printed samples will additionally serve the deterioration research of the partner chair, whose findings will in turn inform the development of the printing process
• You will publish in leading venues, present at international conferences, and contribute to teaching through the supervision of semester and master's projects

• We seek a candidate with a strong background, and ideally a demonstrated body of work, in digital fabrication, and the ambition to treat material behavior as a subject of design research
• You hold a Master's degree in architecture, or in a closely related discipline, combined with substantial design work
• You have genuine competence in building fabrication equipment: the printer will be constructed and repeatedly modified by you, so proficiency in mechanical design and prototyping is essential, and experience with electronics, sensing, or control software is a strong asset
• You are fluent in computational design and experienced in carrying work across the threshold between digital model and physical result
• An interest in the behavior of stone is welcome; its scientific characterization lies with the partner group
• An excellent oral and written level of English is essential; conversational knowledge of German is an advantage.
• As the project involves collaboration between research groups and field practitioners, strong communication skills and a genuinely collaborative disposition are essential

The Chair for Digital Building Technologies within the Institute of Technology in Architecture conducts research at the intersection of computational design, materials, and construction-scale fabrication. Over more than a decade, the group has developed and operated powder-bed and extrusion-based printing systems at architectural scale, with built results including the tallest 3D-printed structures in the world. In-house expertise in mechanical design, electronics and software, together with complete workshop and prototyping infrastructure, allows research ideas to move directly from concept to machine to printed artifact, and doctoral researchers are given considerable latitude in shaping that trajectory. Our highly diverse and international group offers extensive networks within ETH and internationally. We are committed to diversity by offering flexible working hours, home office options, and other measures to ensure team members can perform their roles effectively.

We look forward to receiving your online application with the following documents:

- Cover letter
- CV
- Portfolio of design and fabrication work (max. 20 MB)
- Names and contact information (email address) of three references

We would also like to get to know you better and would therefore ask you to send us a short video of no more than two minutes. We do not expect a professionally produced video; even a recording made on a smartphone is perfectly sufficient. A brief introduction of yourself and your interest in the position should be included. Please then upload the video to a platform of your choice (Dropbox, YouTube, Vimeo, Google Drive, etc.) and include the relevant URL link in your cover letter.

Further information about Digital Building Technologies can be found on our website. Questions regarding the position should be directed to Dr. Pietro Odaglia, email [email protected] (no applications).

Please note that we exclusively accept applications submitted through our online application portal. Applications via email or postal services will not be considered.