Device for cell culture under variable mechanical stress by controlling deformation on its substrate

Abstract

Mechanotransduction can enhance cell cultures when its substrate is subjected to dynamic strain. This paper presents the design and implementation of a device that applies variable mechanical stress on a flexible biocompatible substrate. An embedded system implements a closed-loop PID control that acts on a proportional valve. The valve regulates the negative pressure in a chamber, generated by a miniature vacuum pump. The top cover of the chamber is a membrane that deforms according to the vacuum and is used for cell culture. The elastic modulus of the produced membrane was 260 kPa, similar to soft biological tissue. The deformation of the membrane was quantified by image processing and a linear pressure-deformation relationship was achieved (r > 0.99). The controller was designed based on the identified actuator's dynamic and allowed variable deformations on the membrane with an amplitude of 20 % and a frequency of 2 Hz, selected by the user. The implemented device is PC independent and has a cost, size and weight almost two orders of magnitude lower than a similar commercial version.