Conductive films were prepared on stretchable substrates by mixing sonicated multiwall carbon nanotubes (MWCNTs) with room‐temperature‐vulcanized silicone rubber. Microscopic investigations show a broad range of MWCNT particles with diameters in the range 15–17 nm, lengths from a few nanometers to a few micrometers, and thus a high aspect ratio of 55–70. The sonicated MWCNTs have 40 wrapped graphene layers and an out‐of‐plane correlation length of 13 nm. Also, the grain size of the dispersed sonicated MWCNTs is around 35 nm, and the roughness is around 13.5 nm. At 3 phr, the modulus is higher for the MWCNTs (5.95 MPa). The electrical resistance of the MWCNTs is as low as 180 Ω at 3 phr. These improvements were introduced in an actuator and energy harvester for industrial applications. The actuator shows a displacement of 2.18 mm at 10 kV. At 60% strain, the energy harvesting is 1.07 V during compressive strain and 0.015 V during tensile strain. From durability tests under 30% compressive strain, the voltage drops from the energy harvesting device are negligible for up to 3000 cycles. © 2018 Society of Chemical Industry