Introduction
For Guggi Kofod, founder of the startup Pliantics, the real hurdle in developing artificial muscles isn't materials science, but the slow pace of experimentation. Pliantics, an ARIA-funded Creator, are developing electrostatic actuators: wafer-thin stacks of material that contract like a muscle when you apply a voltage. To iterate on their designs effectively, the Pliantics team needed a new kind of lab tool - one that makes physical testing as fast and iterative as writing code.
The world of soft actuators is inherently unpredictable. Simulation methods like finite element analysis struggle with the large, non-linear deformations involved, and micro-scale flaws lead to unpredictable failures like delamination or electrical breakdown. These factors make predicting actuator behaviour a challenge. Pliantics run an intensive test-driven design process to overcome these challenges.
But manual testing is a time-consuming process. Each change to material thickness, pre-tension, or electrode design requires a new physical prototype and subsequent testing. Pliantics needed a way to rapidly and safely explore these variables using a piece of equipment that didn't yet exist. The core requirements for this custom testing machine were clear, and crucially, it was needed quickly.
Amodo’s Engineering Response
We responded by creating PLIFUNC - a fast flexible test machine to power artificial muscles and subject them to a range of tests, designed to expose the behaviour of Pliantics’ new actuators. The machine was intended to be an everyday workhorse that could surface results and insights in just 15 minutes.
How does it work?
- Mounts the artificial muscle sample into PLIFUNC.
- Connect the high voltage supply to the muscle’s inputs.
- Apply mechanical loads with weights via a pulley.
- Writes custom voltage profiles to a memory card, and insert it into the machine.
- The muscle is ready to test.
- Close the HV safety lid.
- Test begins.
- As the artificial muscle is stimulated with high voltage it contracts, lifting up the weight whilst its extension is precisely measured.
- After the test completes, the researcher can rapidly mount another sample for testing, and repeat.
The forces and displacements involved are incredibly small, often imperceptible to the naked eye. The ability to distinguish single grams of force and micrometer-level changes in length is vital for successful experimentation. Achieving this level of precision and accuracy required significant engineering effort.
The Impact
The development of PLIFUNC wasn't just about building hardware; it was about building Guggi's lab capabilities. A close collaboration, using agile development with weekly reviews, ensured the machine met Pliantics' specific needs. The result is that Pliantics now routinely conducts actuator tests, going from a hypothesis to tangible data in just 15 minutes.
Impact: Before and After
Engineers working alongside scientific terms can change how research happens. In this case, Amodo’s work shrunk feedback loops, enabling scientists like Guggi to de-risk bolder hypotheses. PLIFUNC didn't provide the answers directly, but it enabled Pliantics to ask, and answer, far more questions in the same timeframe.
Amodo are now evolving PLIFUNC’s design. We are scoping the addition of dynamic controllable loads, with ideas being discussed with Pliantics for automatically generating stress/strain curves, automatic spark-recognition via video feed and a cloud-dashboard for experimental data.