Aimée Sakes

While originally contemplating to study veterinary medicine, rising star Aimée Sakes is perfectly at home as an assistant professor within the Bio-Inspired Technology group (BITE) at TU Delft, within which she also obtained both her master’s and PhD degree with honours. ‘I am still very much intrigued by animals,’ she says, ‘but mainly from an engineering perspective. How do they achieve certain mechanical feats, such as pushing an egg through a very narrow and long tube? And how can we replicate their mechanisms and put it to good use?’

A mighty hammer

Her main focus is the development of novel catheters for minimally invasive surgery and her research has resulted in a number of novel prototypes. During her PhD she focussed on an improved treatment for a severe form of coronary artery disease in which the artery is (almost) completely obstructed by plaque that has subsequently hardened through calcification. ‘The request for an improved treatment option came straight from the clinic as it currently comes down to performing something close to open heart surgery or doing nothing,’ Sakes says. ‘We developed a tiny hammer drill, attached to a one-meter-long flexible catheter. The large force needed to create cracks in the plaque is transferred through the catheter by means of a hydraulic pressure wave. It is inspired by the mantis shrimp, which also uses a pressure wave to propel a hammer-like appendage in order to break the hard shell of a crab.’

Eating away at a tumour

Sakes and her colleagues are currently developing a so-called tissue transfer device. The idea is to take tiny bites out of some tissue or growth deep within a human body – such as a cancer – and transfer these bites out of the body. ‘Current technology is based on suction,’ she says, ‘but the longer and thinner a catheter gets, the lower the suction force will be at its end. The pieces that are removed can also get stuck within the catheter due to friction.’ Their solution is based on the long and slender stinger that some wasps use to both drill into wood and to transport and lay their eggs. ‘Tissue transport in our device is based on repetitive back-and-forwards motion,’ she says. ‘It doesn’t suffer from friction; tissue transport is driven by friction! It is, however, still a challenge for us to integrate this tissue transport within a self-propelling catheter.’

Convergence to fill in the final gaps

Not all her ideas are inspired by nature, but most of them are. Sakes has close ties with the Experimental Zoology group at Wageningen University. ‘Sometimes they bring some biological mechanism to our attention,’ she says. ‘And sometimes, when the underlying mechanism hasn’t yet been unravelled, we jointly come up with a hypothesis, build a prototype and uncover a piece of biology.’ Sakes typically takes her ideas all the way up to a working prototype, subsequently contacting commercial partners to develop it all the way to a medical device. But to minimise their risk, companies would prefer for a clinical study to already have been completed. Sakes: ‘I expect that the convergence of TU Delft with Erasmus University and Erasmus Medical Center will make it much easier for us to demonstrate our prototypes on animal tissues and human tissues, thereby filling this gap.’

With flying colours

Together with Michaël Wiertlewski, Sakes recently obtained a ME cohesion grant, which aims to foster interdisciplinary cooperation. ‘Biomechanical engineering, material science and robotics are a powerful combination,’ she says. ‘It is a combination I also enjoy within the Dutch Soft Robotics Consortium of the 4TU federation.’ Whereas her research is progressing at great speed, most of her hobbies – such as travelling and snorkelling – have come to a complete standstill due to COVID-19. Having a private pilot license she can, however, still enjoy her aerobatics, making twists and turns in the air much like her catheters do in the human body.