I came across a TedTalk titled ‘The artificial muscles that will power robots of the future’, which made me think – robots don’t look human at all, is there really a way to do that? An artificial muscle which is cheap, easily constructed and versatile? It cannot be?!

Many advances to improve the look of robots are already ‘in motion’. The invention of the Squidbot in 2020, was made to mimicked the swimming of a squid. The Pneumatic Artificial Muscle (PAM) was designed to aid the rehabilitation of patients diagnosed with polio. However, the HASEL actuator stood out to me, due to its versatility with its use, and the potential it has for improving both quality of life and broadening professional career paths for athletes. The concept of the HASEL (Hydraulic Amplified Self-healing ELectrostatic actuators) provides an unseen side of robotics, making the newly advancing AI robots look last season!

Their first prototype, Peano-HASEL actuator, was designed to contract linearly after electrical stimulation. The dynamic properties mimic those of an anatomical muscle. The elastomeric shell makes it easily recoverable from any force, comparative to the quick relaxation of the human muscles. The voltage applied to either end causes the liquid to migrate, producing a ‘contraction’. I believe soft robotics will go a long way for creating future real-life animatronics, which could even have the potential to function better as a result.

It doesn’t stop there! The Planar HASEL actuator was made to lift heavy objects. Electrical charge is applied to the insulating liquid, causing stretching of the polymer and horizontal shrinking, making it move vertically. The future for this specific design is bright; It could completely replace upper arm prosthetics for everyday use! It can even collect enough force to throw a ball in the air, supporting my opinion: the benefits of this development will be transitional through generations!

The Quad Donut HASEL prototype can run on superspeed – put it this way, when I saw the video I couldn’t tell it was moving! It has a circular shape, and each ‘pod’ lies on top of one another. As the voltage is applied, liquid migrates to either side causing the ‘Donut’ shape. One improved function is the smoothness of motion. The mechanics allows for great control, helpful for picking up delicate objects. If this doesn’t show elegance, I don’t know what does! After seeing this photo, my thought was that if this is simple HASEL technologies, surely it can be developed for both everyday and professional use? Not only improving mental health but broadening delicate skills such as chess! I don’t see the harm in trying to improve already invented prosthetic designs! And it gets better! The use of the thermoplastic polymers for the bags provides a low-cost production alternative to current prosthetic materials such as carbon fibre which, although durable, are extremely stiff. (Rothemund et al., 2020). Of course, with every invention, there are ALWAYS drawbacks, especially one with increasing pressures to be ‘perfect’ in today’s research era. One is the lack of temperature resistance. My proposal is to add a thin heat-resistant film, to prevent it becoming rigid whilst also becoming durable. Incorporating outer metal gratings for flexibility would allow contraction and protection. This increases sustainability of the HASEL, whilst maintaining the excellence of mechanisms intact. The hope is that HASEL will lend a helping hand to those who need it!

References: Rothemund, P., Kellaris, N., Mitchell, S.K., Acome, E. and Keplinger, C. (2020). HASEL Artificial Muscles for a New Generation of Lifelike Robots—Recent Progress and Future Opportunities. Advanced Materials, 33(19), p.2003375. doi:https://doi.org/10.1002/adma.202003375.