Designing a prototype capable of lengthening in vitro 3D engineered human skeletal muscle tissue

Researchers are able to grow small muscle tissues between two attachment points and make them contract using electrical stimulation. Currently, these attachment points are static. However, a core function of muscle tissues is their ability to change length; current devices to investigate in vitro 3D engineered human skeletal muscle tissues are not able to assess how this core function is affected during the experiment, for example, after adding a drug or aplying a electrical/mechanical stimulation to the tissue. To be able to perform this function, a prototype system was designed which is able to change the distance between the attachment points. Being able to do this opens up countless possibilities for investigating tissue behaviour, from eccentric training (lengthening the tissue while electrically stimulated) to immobilisation of the tissue at a certain length. To assess how the tissue reacts to this, the force it can generate is an important metric, therefor the designed prototype is able to determine this force. A list of functions and requirements for such a system is composed, after which it is used to design a system that should be able to fulfil them. The design is based on two parallel flexure guides; one is responsible for measuring the force, and the other for altering the tissue attachment point separation. The motion is actuated using a micro stepper linear actuator. The prototype was made, and initial tests were done to verify mechanical performance. It was concluded that the current prototype has limitations, but can be used to perform tests with and improve the design.