Extracting all individual layers from a Raster Brick File

I have stacked 28 layers to a brick in R

brik
class      : RasterBrick 
dimensions : 720, 1440, 1036800, 28  (nrow, ncol, ncell, nlayers)
resolution : 0.25, 0.25  (x, y)
extent     : -180, 180, -90, 90  (xmin, xmax, ymin, ymax)
crs        : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0 
source     : C:/Users/Ujjal Baruah/AppData/Local/Temp/Rtmp0GaiPO/raster/r_tmp_2020-01-03_030159_46788_10398.grd 
names      : Data.Fiel//tNO2Trop.1, Data.Fiel//tNO2Trop.2, Data.Fiel//tNO2Trop.3, Data.Fiel//tNO2Trop.4, Data.Fiel//tNO2Trop.5, Data.Fiel//tNO2Trop.6, Data.Fiel//tNO2Trop.7, Data.Fiel//tNO2Trop.8, Data.Fiel//tNO2Trop.9, Data.Fiel//NO2Trop.10, Data.Fiel//NO2Trop.11, Data.Fiel//NO2Trop.12, Data.Fiel//NO2Trop.13, Data.Fiel//NO2Trop.14, Data.Fiel//NO2Trop.15, ... 

Now, i want to save this individual layers in Geotiff using

writeRaster(brik, file.path('/output/filepath/', names(brik)), bylayer=TRUE, format('GTiff'))

Unfortunately, i get just one file instead of multiple layers in geotiff.

Any solution would be appreciated. Thanks