Research has shown that the success rate in many types of surgeries is strictly related to the experience of the surgeon. However, early in their career, trainees are not given the opportunity to operate on a sufficient number of patients nor to perform an exhaustive mix of procedures. The scenario has been further worsened by the reduction of assisted training hours in Europe (since 2009) and US (since 2011). Training and technical tasks are usually practised on cadavers, animals or using virtual simulators. However, all these alternatives present difficulties: limited availability, expensive handling and preservation processes (cadaveric training), nonhuman anatomical structures (animal training), costly set-up, and doubtful skills transfer to the real operating theatre (virtual simulators). A potential solution is to promote the use of artificial synthetic models, also known as phantoms. Phantoms are reproduction of human parts and organs that allow the trainee to practice positioning of the anatomical structures as well as hand coordination. Unfortunately, they lack of reliable tactile feedback (e.g. palpation) and real tissue deformation patterns which critically reduce the fidelity of the surgical training. The main objective of this project is to overcome the present limitations by developing phantoms capable of providing detailed anatomical structures along with an accurate tactile response when performing surgical tasks such as cutting, indention and suturing. The proposed investigation is aimed at designing, making and testing synthetic advanced materials tailored to reproduce the mechanical response of different human organs and tissues (lung, brain, liver, skin, cartilage, etc.). Direct comparisons with experimental data on organic tissues and feedback from a number of experienced surgeons will be used to validate the effectiveness of the proposed solutions during this research journey towards safer surgeries.

I participated at the European Research Night in 2019 in Milan and it was an amazing experience. I had the opportunity to disseminate my work and explain what I do to both scientists and member of the public, including younger students and kids. Unfortunately it was not possible to replicate the experience in 2020 because of COVID and travel restrictions. Therefore Politecnico of Milan in collaboration with a great EU outreaching team organized a virtual (online) MEETmeTONIGHT 2020. I agreed to participate and made a video explaining what Alpha-stem is about. I also contributed by being available online via Teams to member of the public audience that would connect to the virtual rooms and ask questions about the research. It was not the same as having the event in person but it was nevertheless enjoyable! Here’s the video!

The fellowship allowed me to reinforce existing ties with old collaborators and establish new ones all over the world. Many people that I have met in Harvard, Polimi and Imperial have now taken up academic positions in different parts of the globe, especially the US and EU. These people are now part of my network of collaborators on which I can rely on for organizing events, sharing data and producing cutting edge research to tackle the next big challenges.

Unfortunately, due to COVID and the unavailability of the labs for a considerable chunk of my fellowship, not all the objectives I had planned have been achieved. In particular it was impossible to produce the final surgical phantoms but I managed to deliver all the other objectives. I am still working on completing the last part of the work and I am very close to submitting a paper on airways optimization for lung phantoms. Most of this work was completed remotely using simulations but I will be starting the manufacturing of the phantom very soon.

I had the opportunity of expanding my knowledge and conduct fundamental research on mechanical metamaterials, including architected tessellations, origami and kirigami patterns and chiral and arabic motifs. Two main publications came out of this work: a PNAS paper where we explain the formation of domain walls in rotating squares patterns and an Advanced Materials paper about inflatable kirigami. Both the works sprung out from initial investigations on these exotic materials with the aim of using them for the surgical phantoms. I also got the cover of the journal!

Something that I started investigating during the fellowship and I am still working on is the use of machine learning to guide the deformation of a material during pressurized inflation. This is an idea I wanted to pursue in order to achieve a realistic inflation volume when inflating my lung phantom. It turns out that the problem is not trivial at all! It involves the inverse mapping of 3D deformations to an infinite number of possible combinations of stiff and soft pixels on a regular grid. Neural Networks are great to solve this type of problems employing only a minimal number of datapoints. The paper is now under preparation and will be hopefully out soon!

A. Mazier, A. Bilger, A. E. Forte, I. Peterlik, J. S. Hale, S. Bordas (2021). Inverse deformation analysis: an experimental and numerical assessment using the FEniCS Project
arXiv preprint arXiv:2102.13455 (Under Review on Engineering With Computers)

B. Deng,*, M. Zanaty,*, A. E. Forte, & K. Bertoldi (2021). Topological solitons make metamaterials crawl. (in press)
Physical Review Applied

L. Jin, A. E. Forte & K. Bertoldi (2021). Mechanical Valves for On-Board Flow Control of Inflatable Robots.
Advanced Science

M. Terzano, A. Spagnoli, D. Dini, & A. E. Forte (2021). Fluid–solid interaction in the rate-dependent failure of brain tissue and biomimicking gels.
Journal of the Mechanical Behavior of Biomedical Materials

A. Dine, E. Bentley, L. A. PoulmarcK, D. Dini, A. E. Forte*, Z. Tan* (2021). A dual nozzle 3D printing system for super soft composite hydrogels.
Hardware X

B. Deng^†, S. Yu^†, A. E. Forte, V. Tournat, K. Bertoldi (2020). Characterization, stability and application of domain walls in flexible mechanical metamaterials.
PNAS

A. E. Forte^†, … & K. Bertoldi (2020). Kirigami-inspired inflatables with programmable shapes.
Advanced Materials

Z. Tan, J. P. Ewen, A. E. Forte, S. Galvan, E. De Momi, F. Rodriguez y Baena, D. Dini (2020). What Does a Brain Feel Like?
Journal of Chemical Education

28/01/2021 – Studying softness through many lenses, University College London, Department of Mechanical Engineering (ONLINE)

22/10/2020 – Studying softness through many lenses, King’s College London, Department of Engineering (ONLINE)

10/08/2020 – Studying softness through many lenses, Warwick University, Department of Mechanical Engineering

17/07/2020 – From Neuroscience to Radical Matter – embedding functionality at the design level, London South Bank University, Department of Mechanical Engineering (ONLINE)

20/02/2020 – From Neuroscience to Radical Matter – embedding functionality at the design level, Imperial College, Department of Bioengineering

07/02/2020 – From Neuroscience to Radical Matter – embedding functionality at the design level, Boston University, Department of Mechanical Engineering

18/10/2019 – Kirigami Balloons, Boston University, Moss Lab

25/02/2021 – I was invited as as “keynote speaker” and presented (virtually) at the 1st Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM21, Timisoara, Romania – Manufacturing and printing of super soft materials for mechanical tissue‑mimicking applications

22/09/2020 – I was invited as “keynote speaker” and presented (virtually) at the MSE 2020 – MATERIALS SCIENCE AND ENGINEERING CONGRESS Keynote Lecture – Programmable Kirigami Balloons, Materials Science and Engineering 2020 conference, Darmstadt, Germany.

26/05/2020 – I was invited as “speaker” at the EMI 2020 – Columbia University – Origami/Kirigami Inspired Structures and Metamaterials mini-symposium – (Unfortunately cancelled due to COVID-19) Title: Driving balloon deformation through programmed kirigami patterns.

15/10/2019 – Kirigami balloons – Society of Engineering Science 56th Annual Technical Meeting, Saint Louis, Missouri.

Wire-cutting to test the fracture properties of brain tissue and biomimicking gels: experiments and modelling, M Terzano, A Spagnoli, D Dini, AE Forte, 26th Congress of the European Society of Biomechanics, July 11-14, 2021, Milan, Italy

Inflatable Kirigami Structures L Jin, AE Forte, A Rafsanjani, B Deng, K Bertoldi, APS March meeting 2020

Inverse simulation for retrieving the undeformed position for hyperelastic materials: application to breast simulations A Mazier, A Bilger, AE Forte, I Peterlik, J Hale, S Bordas, 14th World Congress in Computational Mechanics (WCCM) ECCOMAS Congress 2020 19 – 24 July 2020, Paris, France

Modular, programmable and inflatable kirigami L Jin, AE Forte, A Rafsanjani, B Deng, K Bertoldi, International Conference of Mechanics of Advanced Materials and Structures 2019

A mechanically accurate 3D brain phantom as an in-vitro scaffold for neural stem cells Z Tan, C Lee-Reeves, AE Forte, D Dini, 8th International Conference on Mechanics of Biomaterials and Tissues 2019